Pull string came off of starter wheel...how do I fix?

I was using the grass trimmer attachment and switched to a brand new brush cutter attachment. Brush cutter was right out of the box. I pulled the start cord only half way and it came off the spool inside the housing and is wedged around the shaft inside. I was able to remove pieces to get close but I can't seem to figure out how to gain access inside to unwedge the pull string. Looks as if a wheel that turns the square drive that ultimately turns the attachment needs to be removed. How do I gain further access to this pull string to rewrap it arounf the starting wheel?