Step 1: .
Unplug the fridge. You can wait until later but don't forget.
Step 2: Freezer door.
It's 4 screws, one in each corner. Just loosen them a few turns - don't take the screws out entirely - it's much easier putting the door back on when the screws are already in place. The door slides up & off.
Step 3: Lower basket.
It lifts out, no tools required. Now's a good time to start eating all your ice cream.
Step 4: Upper basket.
Remove the 2 screws at the front of the rails, then lift up the rails slightly on each side, to slide the basket forward.
On the plastic pieces at the back sides of the upper basket, push in two tabs with your screwdriver on each piece & pop them up. This will let the upper basket slide out off the rails.
Step 5: Icemaker.
Remove the lower screw, then loosen or remove the two screws above the icemaker. Unplug the wire harness where it passes through the rear panel - squeeze the sides of the plug & pull. Lift the icemaker up & out. The water tube will slide out of the guide.
Step 6: Plastic guards.
The thermostat guard is the skinny piece to the upper right. Push in (to the right) the tab on the left side in the middle. The guard opens like a door pivoting on the right edge, & pulls out.
The center fan guard has two tabs at the top on each end that push in toward the center, & another tab in the middle at the bottom of the guard that pops up.
Step 7: Freezer panel.
Remove the 4 screws in each corner. Push the thermostat back through the slot at the top, & also push the icemaker plug back through its slot.
FAST/HARD WAY: Pull carefully up & out from the top middle edge. Be careful because that sucker is SHARP! The back panel will bend vertically in the middle as you remove it, but it's flexible & will pop back into shape.
SLOW/EASY WAY: If you don't like bending the panel around the drawer slides, you can take off the slides. The metal rails have tabs that push in to release the whole slide assembly, which pulls out forward. You only need to take the rail housings off one side - when you go to remove the rear panel, just pull that side first. To release the upper section (that you already unscrewed in Step 4), left it up, bend in & pull out - the back end has a tab through the freezer wall. The lower plastic slide housing unscrews with 4 screws.
Step 8: Ice Dam.
By now you should see the ice problem. Typically the entire evaporator tray is completely iced, along with some of the tubing. MELT IT ALL. Warm water applied with a turkey baster works well. Be careful not to puncture the coils because ... that will ruin your fridge.
Do all the ice melting while the drain is still plugged so it runs out into the freezer floor where you can sponge it up. If the meltwater goes out through the drain hole, it can flood the pan under the fridge - no big deal, just dirtier water & more mess.
The drain hole is near the front of the rear tray in the middle. It's pretty wide (1/2?) & short, only ~2 inches long. It goes straight down into a rubber "duck bill" grommet that's probably plugged up with gunk, that you access from the back of the fridge...
Step 9: Drain grommet.
Pull out the fridge so you can access the back side. Remove the screws (6?) around the lower access panel, pop the power cord up & tilt the panel out of the way. The plastic tray under the fan is the evaporator tray - that's where the water SHOULD normally be dripping into & evaporating from.
Behind (technically in front of) the fan, there's a black drain slide into the tray that leads up to your plugged drain. Push the slide aside to see the drain. There's a rubber "duck bill" grommet on the end. Pull it off & clean it - it's no doubt plugged with gunk. Better yet, trim the opening very slightly so the hole is larger - see this site for photos
Step 10: Put it all back together.
Some tips: if you lived hard/fast & didn't remove the rails & rail housing, getting the freezer panel back in place . Make sure you slide the tray rails all the way out before you start trying to put the rear panel back. Bend the panel vertically along the middle so it springs back into place on each side. Again, wear gloves. Once it's in place, don't forget to run the thermostat wire & icemaker tube/plug out.
When you put the the top tray back, make sure it's all the way to the front before you pop the plastic pieces on each side back down, so the gears on each side are aligned in matching grooves. Otherwise your drawer will be crooked & probably won't slide.
Hope this helps. I have a Whirlpool GX2FGDXVY but these steps work on other models too including Maytag etc.
here is the whole exert video of the whole eplanation watch it,(https://youtu.be/lhuBR1sKx7E)or