Simply open up your toribash installation folder
(default = C:\Games\Toribash x.xx\ (where x.xx is the version number))
then go to the custom folder
(C:\Games\Toribash x.xx\custom\)
then make a new folder, lets say 'TEST'
(C:\Games\Toribash x.xx\custom\TEST\)
then put in your textures
(C:\Games\Toribash x.xx\custom\TEST\head.tga)
then to load them, open toribash and use the command:
/lp 0 TEST
(/lp = load player)
(the 0 = tori, if you replace that with a 1 it will instead load onto uke.)
(where TEST is just put the name of the folder.)