Hello and welcome to just answer. Let me see if I can help you with this. The fitting on the transaxle end requires a special release tool to expand the spring clip that secures the line. However, if you are careful, you can remove the spring clip with a small pic or pocket screw driver. pry the black plastic clip off of the fitting and you will see the spring clip. Then pull the line out of the fitting. You do not need to drain the fluid, but residual fluid in the line will leak out, so lay some shop towels down. You can clean the fluid that has leaked using a can of spray parts wash available from your auto parts store. I hope this helps, and let me know if you need more assistance with this.
Hang on, let me look this up. Yes brake cleaner is ok. I will be right back.
Ok, yes just remove the bolt at the cooler line fitting and pull it out of the cooler. You may need a flat bladed screw driver to help pry it out. There will be o rings on the line's fitting, and if they get torn or damaged should be replaced. When assembling the lines back into the cooler, apply a little trans fluid onto the o rings.