1) Go to settings - applications - enable the 'unknown sources' option.
2) Put the .apk files somewhere on your SD card.
3) Open your file manager on the device.
4) Select Minecraft_Pocket_Edition_v0.1.1.apk and install it on your device.
5) If you get the 'complete action using' pop-up, choose 'package installer
6) Enjoy Minecraft Pocket Edition!
IF you get lost on the way, remember google is your friend