You need Windows to recognise your phone. You can download drivers here if you haven't got them. Make sure all the drivers are in one folder. Now you plug your phone in. Windows will say "New Hardware Found." When it searches for drivers to install, remember to select the folder which you saved the drivers in. You will also need P2K drivers. You can get them here. Put them in the file path "C:WINDOWSsystem32drivers" Now you need Skiman, a program used to put the skins on your phone. You can download here.
You have all the apps, now you need the skins. There aren't many sites which offer free skins, you will have to try and find some. They need to be for Motorola V3, otherwise they won't work. The folder has to have .dat and .ski files. Here is a site you can get some skins.
Now open Skiman. Wait a while and it should auto connect your phone and load some skins. These are the default ones. Now press "Install" at the bottom, a window will come up, just click ok. Now you browse for the folder you have the skins in. It will only recognise the .ski file, so make sure it's there. Wait for it to finish and restart your phone. You can now apply the skin. Some skins labelled for the V3 may not work because they are the wrong resolution. Keep trying different ones and you will find one.