Moddin?

Okay guys i wanna make mods but i cant i prolly dont have the right plug-ins for photoshop... and i wanna put the .DTX file into my Photoshop but i cant says it not tha right kinda document......(anyone kno why?) and i cant do anything else i jus wanna make the Textures on guns....... but i cant get it to open in photoshop (can somone help me?) Ill PRess thanks if i get help?

i fallowed the instructions on were to putt them.... Coudl yuh Tv me and tell me where to put them or accually do it for me? if yer not busy?