I hope this idea will be useful for people like me, well, happy browsing.
Step 1: Parts Fot the Footswitch Mouse
1 platform for support the footswitch
1 switch (game console switch)
Step 2: Soldering and Assembling
1- open the mouse
2- identify the place of buttons or terminals
3- assemble the switch
4- solder the switch to mouse terminals
Step 3: Use the Footswitch
your index finger will be thankful!