How do I put custom guns in my WAD?

Im making a wad called Operation Terrafaux, and i want to switch out some guns, how would i do this.

It depends on what engine (i.e. vanilla Doom, Eternity, ZDoom) you are planning to map for, and on what kind of weapons you want to add.

If all you actually want to do is switch the graphics, you just have to include the new graphics in your wad, with the same names as the ones they replace. If you want to change how the weapons work, you'll need to use Dehacked, or a port-specific definition lump.

It's zdoom.

If the project requires ZDoom, then you could use DECORATE to make or modify weapons.

Aside from the info on those pages, you'll also need the weapon graphics, and a lump manager, like SLADE3, in order to insert them.

i downloaded the weapons from REALM 667.

Then, depending on what they are, you'll probably only need to merge the weapon files into your own WAD with SLADE3.

There might be a more efficient way to merge them (Import?), but you can likely just open both up side-by-side and copy+paste the contents of the weapon WAD/PK3 over into your own WAD, cleaning up any conflicts as they happen.

Thanks dude.

Or, merge in XWE!
Alot easier!