Long story short, I want to make my Mega 2560 into a game controller, but unlike most projects of this kind it's not a generic HID device and I instead want to use drivers for a specific controller. I have a HID descriptor, VID and PID for the device I want to spoof and I've had some success using a Leonardo, but I don't think the hardware is appropriate for my application so I want to move over to a Mega 2560 instead.
What I'm looking for is a guide similar to this: http://forum.arduino.cc/index.php/topic,111.0.html and/or similar resources so I can essentially modify them with the specific descriptor and IDs I need. I've found quite a few but they're out of date now, so I'm pretty much just asking for some guidance to find something that I can use as a starting point with a 2560. Also the linked guide assumes maybe a little more knowledge than I have... Not a lot more, mind you, but even if the software he linked wasn't out of date now I'd still have no idea what "Do Tools[ch8594]Make clean" means.
I should point out that I first started this project back in 2015 but got a job early last year that sapped most of my free time, inspiration and desire to do more electronics work at home so I haven't touched it since last summer, so everything I learned about USB and all my memories of modifying Arduino files to give the Leo the new IDs... That's all pretty much gone from my brain now, sadly. In fact I've barely done any Arduino work since then so I'm a little out of the loop.