Hi Jeff, DONT pull the window out and if you do, refit it before you replace the felts.
Inside the door assy you will find a stop which stops (funily), the window from dropping down to far. You will need to move the stop out of the way and allow the window to go down below the belt line, it may even need to come out of the tracks (been awhile so cant remember). Then remove the old felts, they will need to be pried out and the new ones will probably need to be cut and finnished, use the old ones as an example.
nassi