Mass changing aircraft types

[pilotcraig]

I know this was covered in a previous post, but I can't seem to find it. I have two aircraft types set up; one for instructing, the other for non-instructional flights. Same A/C, but the autofill options are different. The time has come to merge them all into one type, but I can't figure out how, or find the post I saw that said how I could do it.

If you could point me to the thread, or just give instructions, I would appreciate it very much.

Thanks

Edit: I tried changing the A/C type names to match in options but it won't save the new name, just reverts to the old one.

Edit2: Just noticed I posted in the wrong forum. Sorry