Took the chain tensioner off to grease it and Wow! it was a real Bi$^&! to get back on. Anyway, I had to put the spring on upside down and work it around into position. Anyone come up with a better way?

Nope, I am not sure about the upside down part, but can agree it is nothing but a bear at best.

I put the spring on without it being hooked over the tensioner first (sitting beside the tensioner, flat on the swingarm, then when I get the bolt into place, take a hook or pair of vice grips and pull the tensioner spring onto the tensioner arm.

I was trying to find a better way myself last Saturday.

I worked out this way for a GG,I'm sure something similar would work on Sherco etc. Slide a length of small diameter steel tube aprox 6mm. bore over the spring tail.(or can use a small old fashioned cranked ring spanner). Holding this in your left hand then hold the tensioner pad in your right hand,with spring installed on central bush. Then move your hands together,compressing the spring,hold in place over the threaded hole in the swingarm. Then get Alexz or whoever to run the mounting screw in with a "t" bar . May take a couple of goes but we usually manage it first time like this. Doing it this way the spring is not at all distressed or weakened by levering or leaving it unhooked and then cheating it on.

I simply used 3 zip ties and cut them when the spanner was mounted