My starter pulley was broke i replaced it with a

Video links at the bottom of this feedback.
Turn Off the Ignition: Move the ignition switch on the Craftsman trimmer into the "Off" position.
Remove the Starter Assembly Cover: Use a screwdriver to unscrew the starter assembly cover and remove it from the trimmer.
Prepare the New Pull Cord: Cut off the old cord from both the pulley and the starter handle. Dispose of the old cord.
Replace the Pull Cord: Flip the starter cover over and replace the pull cord. Make sure it's securely attached to the pulley.
Reassemble the Starter Assembly: Put the starter assembly cover back in place and secure it with the screws. How to Replace the Pull Cord on a Craftsman Weed Trimmer (youtube.com)

WS 2400 (CMXGTAMDSS27) (41ADSS27793) - Craftsman String Trimmer Parts Lookup with Diagrams ' PartsTree

can you just wind the spool a new rope , im not that familiar with this newer equipment however some thing only change a little.

Put a socket and wrench on the crankshaft pulley bolt, and see if you can turn the crankshaft-clockwise. If the crank won't turn, something internal is bad. If you can turn the crankshaft normally, check that another pulley has seized.
Or try it this way: take the serpentine belt back off and see if the starter can spin the crankshaft. If it does, look for a seized pulley. If a good battery cannot make the starter turn the crankshaft, likely the motor is shot.

Good luck! This model usually requires the muffler being removed,the right side of the engine disassembled.... A hint! do not remove the recoil spring unless it is broke. Turn the rope pulley clockwise about 6 times alaign the rope hole in the pulley and the starter housing , push the rope through, it helps to melt the rope ends.after the new knot is tied and pulled tight,gently release the pulley.

Did you replace the idler pulley or the belt tensioner? If it was the idler pulley, make sure you transferred the insert that centers the bolt. If it was the tensioner, there is a nub that must fit into a slot on the engine block to keep it flush

find the bolts attaching the bracket to the engine (possibley2 or 3) Buy a genuine replacement assy and fit get a new belt as the old one may have suffered damage. Replace where you removed the broken bit and adjust the belt to the correct tension

There should be a hole in the pulley that holds the starter rope in the starter/recoil unit. If you have taken the machine apart to that point, yes, there is only one way to reassemble it.
You will have to wind the starter recoil without the rope installed on itabout 5-6 complete revolutions to "pre-load" tension on the spring-steel starter spring, then lock the pulley in place, insert the pull rope and tie it off so it can come back out and then release the pulley, letting it draw in the new starter cord. Make sure you have the handle installed so it will stop when it gets to the body of the engine cover.

Remove recoil assy. Turn the cord pulley in the reverse direction and hold in place, take your new cord and snake it through the holes and tie a knot on the end now put they other end through the plastic hand puller and tie a knot, Release the pulley and install.

I don't know exactly what you have there, but starters in general work pretty much the same. What you have to do with any starter when you replace the rope is to first wind up the spring with the pulley. Turn the pulley in the direction it would be turning if you were pulling the rope. When it's wound tight, back off to align the rope hole in the cover and the pulley. Stick the rope from the outside through the cover and pulley and tie a knot. Then let the spring tension pull the rope into the starter. Hope that helps. Dwain

If your rope broke, there was no reason to take the spring out. The rope can be replaced just by taking the rewind housing off, turning pulley to get rest of old rope out, wind the pulley (and spring) the direction the rope would be pull it when starting. Then , when it's wound tight, back off to align the holes in pulley and cover. Hold it there, stick about an 8' piece of rope from the outside through the pulley and tie a knot. Hold the rope and let the spring pull the rope back into the starter. an tie handle back. Take your housing, and spring to a shop. They can re-install the spring and put on a rope a heck of a lot cheaper that buying that whole assembly.