is there a DIY on this forum and what is the best fluid to replace stock with

 

Redline MT-90 is the best. There are posts on how to change the fluid. It's not difficult. You only need a 24 mm socket for the drain/fill plugs and a pump to get the oil in. If you go with a different gear oil (use a GL4!) in a gear oil bottle, you can probably use the bottle tip to fill.