Change Model Texture Help

[Ergic]

hey guys

im editing a model of WC3 in Mdlvis and i want to change the units texture in the uvmaps is saw 2 blp files in the list of textures the model uses and i want to edit the models hand texture so i wanna use the other texture example the hands uses the abc.blp texture what i want is use the other one the xyz.blp how can i change it??? or maybe just how to add another texture?

tnx in advance