I need to replace the hinge pins in my 2000 yukon suv. I have a kit from NAPA, but I need some pointers on how to get the old pins out and install the new ones.

The only door bushings I am aware of are the ones on the hinge pins. Correct? If not, please clarify what you mean.
New pins come with new bushings, and the hinges are welded on so the pins are pretty much the only items replaceable. Not a fun job - because of the door stop springs you will need a spring compressor, and you will also need a special tool to drive out the old pins. However, both are available from a parts store or Amazon.
Just open the door and support it from the bottom, and then go for it, one pin at a time - for the upper pin, compress and remove the small spring, drive out the old pin, drive in the new pin and put the spring back. No spring on the bottom hinge - just replace the pin.

You can buy a hinge repair kit at most good auto parts stores.

You will have to support the door while open, and remove the pin from the bad hinge. Most kits then require you drill a hole where the pin was and press in a bushing. Reinsert the pin (or the new pin if your kit came with it) and remove whatever was supporting your door.

This can be done with one person if you're careful, but it's easier if you have a helper to keep control of the door.

You can also remove the hinge completely on certain vehicles, allowing to repair the hinge at a workbench.

You may have to replace the hinges but most aftermarket suppliers have pin and bushing kits to repair your existing hinges. A phone call to your auto parts supplier can probably fix you up for a fraction of the price of new hinges.

When you go about fixing the door, an old bumper jack is the best tool to use, if you have one. It will support the end of the door while you remove hinges and make adjustments.Otherwise you will need a helper. BE SURE to mark the position of the hinges before you remove them so you can put them back on easily. If you don't mark them it can take a looooong time to get them adjusted properly. Hope this helps.

go to NAPA Auto Parts and see if they have a kit made by Gabriell shocks for your truck

The hingepin is available in some of the help kits at the parts store. If you are just trying to make the door tight again there is no reason to unbolt the hinge. You just grind or chisel the top shoulder of the pin away and then punch the old pin through the bottom.

Put the new pin through the hinge and bend a shoulder on the new pin. Some may even use a nut with threads.

To install the pin or replace the hinge you should open the door and try to brace the bottom of the door with a bucket or books or anything where you can keep the door from changing position. Once braced, a hinge will just unbolt and you can swap it with the new part. Do one hinge at a time if you have 2 on a door.

its not bad to do it yourself. but it will take 2 people to do it. have your helper open the door and lightly lift it up so the pin is free then slide the pin up and out and then the door can move off the hinge so you can get the old brass sleeve out and replace it with the new one and slide the door back on and replace the pin. i would only do one hinge at a time and do the bottom one first.

Most auto parts stores have hing pin replacment kits. they are easy to put in. you need one helper and a floor jack. i got mine at napa they had a KD rack with KD tools and parts on the rack.

Most likely the hinge is not bad, but the hinge pin bushings are bad. You can buy the hinge pins and the bushings at your local auto parts store. They come in a kit. Hope this info is helpful.