I have a 9877 model trimmer i cant figure out how to use the trimmer do i unscrew the head and flip it around to use???

There should be a small hole on the top of the strimmer head. Put a small screwdriver in the hole as far diwn as you can then spin the head till the screw driver drops down a little more . Once you have done that the hole head will unscrew.

you buy spool of line and thread your self, you maybe able to buy the spool already has string on the spool, most are basic, the spool should have the direction you need to string it.unplug the trimmer, turn up side down, it have nut on it, unscrew it counter clock wise, than pull spool off restring the line for the weed eater, the string must be wound counter clock wise from the direction the weed eater or trimmer spins.

www.ask.com/mfg.name/make/model/change/head/trimmer/

Unscrew the head's center bump-knob counterclockwise with your fingers. Pull the bump knob off and take the spool cover off the head. Slide out the spool and any remaining cutting line. Lift out the spring underneath the spool. Take out the slide washer. Unscrew the arbor bolt either clockwise or counterclockwise, depending on model, in the center of the trimmer head using the wrench. Take the entire head off the end of the shaft.

Your old head should simply unscrew from the gear box. You should not have to disassemble the head to get it off. Some models have a small hole above the gear box where you can insert a small screwdriver to lock the drive shaft so that the entire unit stops spinning. Keep in mind that some models have left-hand threaded heads while others have right-hand threaded heads. In most cases, you'll unscrew the head opposite of whichever way the head normally turns while you're trimming. This is by design so that the machine doesn't unscrew the head itself while you're using it. You can find replacement heads for most makes and models of trimmers at PartsBuggy.com.

Unscrew the 4 screws from around the primer, the primer and the primer base should just pull off, there will be a diaphram under neath.

your strimmer head has rounded where the bolt is located.You will need a new head so you have to break the plasic to get at the bolt and fit a new head.

There is a nut above the head, place a wrench on the nut then unscrew the head from the shaft, unless yours is different from mine this is how it works. I hope this helps.

There is a round, rotary black part between the metal piece to which the cutting head attaches and the outer plastic seat of the cutting head. There are two square slots, each about a quarter inch wide, on opposites sides of the black piece. Slide an Allen wrench or something similar firmly into the slot. Holding the Allen wrench in a stable position, turn the outer plastic ring of the cutting head (it has scalloped edges that can be gripped firmly) counter clockwise to unscrew the cutting head from the bolt on which it is mounted. Be careful with the tool (e.g. Allen wrench) used to hold the black piece steady, as it is plastic and could be damaged by the edge of the tool.

You have to wind the rope assembly then slip it over the shaft! attach the screws on the outside of the assembly usually four screws. then your good to go. if the assembly doesn't wind up then you need a new pull cord assembly. If it winds up but doesn't pull once it's assembled, you have it in backwards. remove it and flip it around wind it and try again!

unscrew 'clockwise'..... the opposite way that you would normally unscrew something