I put a bend in the washer so it would grip the wire. I also had to dig into the new float so that the washer could be recessed into the float. 30 miles later and it is still working.
The new float is some type of non-cork composite material. It is not hollow but easily can be hollowed out. To recess the washer (which you may need to do because the new float is longer than the original cork float and the crimped line doesn't stick through the float enough to replace the washer) I just took a screwdriver and gave it a twist around the existing hole. The new float material gave way readily. If I had a solder gun I would have added a drip of solder to the wire/washer as well.
use a pair of vise grips and round out he wire to get the washer off cut into the back side of the new float so it can go on far enough to get the washer back on and flatten the wire out again just like it was originally,