Removing Sleeve Hitch
 

It is very hard to remove the pin that holds the top link in place?

I want to move the Sleeve Hitch from my 149 to the 129.

no, not hard at all. it should just be a cotter pin.

It sits under the battery and is rusted badly.

make sure the pin hole is clear of what should be a 1/8" cotter pin, use some liquid wrench or pb blaster to loosen it up. may try a strap wrench to get it to turn but it should just slide right out.