1. Download this mod and 'Trevor Phillips Player.img (by M.T.H) for Android' mod.
http://www.gtainside.com/en/sanandreas/mods/114540-trevor-phillips-player-img-by-m-t-h-for-android/
For the installation of tattoo mod, you may edit 'player' folder of 'Trevor Phillips Player.img (by M.T.H) for Android' mod.

2. Open 'player.txt' file from 'player' folder by txdfucker.

3. Import (with alpha) all png images in 'png files to player.txt' folder. Overwrite all the images and exit txdfucker.

4. Copy 'data' folder to your 'phone\Android\data\com.rockstargames.gtasa\files\'.

5. Copy 'player.img' file to your 'phone\Android\data\com.rockstargames.gtasa\files\texdb\'. 

6. Copy modified 'player' folder to your 'phone\Android\data\com.rockstargames.gtasa\files\texdb\'.