I really like my little droid. I think he's awesome. The process of gearing him up can get quite frustrating though. I feel like in most cases it's hit or miss with this little dude. Most of his slots are duplicates. I'll get a motor to replace the older/weaker one and it ends up replacing the other one. I try drag n drop and I get the whole "this doesn't go in this slot" message. How am I supposed to know what piece replaces what so I'm not gambling every time I have to spend some credits? Is there something I'm missing? Can someone please help me out? Thanks in advance.

Each slot has a name, those also happen to bein the items names.