2 things. halo doesnt need matchmaking moders yet. and if you just wanna do a few forge mods you had better have 55 bucks for a transfer cable 100 for a hard drive and 100 dollars to get unbaned for...
Yes, it is possible to mod Halo: Reach. There is a program released today, called Horizon 360, that gives you a variety of campaign mods. Multiplayer mods are still being worked on. Campaign mods...
You can mod Halo Reach with a Jtag, A Modded controller from GamingModz or another Hacking device, The Only thing is just don't go online because people will report you and you will get banned!