Questions: 2001 Protege/5 Speed Trans Oil Change/Fuel Filter/Wireless Door Locks

[carhelp4me]

Hello. I have a 2001 Mazda Protege and I need to find out how to change the 5 Speed Manual Transmission Oil in it and where the plug to do so is?

I also need to find out how you change the Fuel Filter on it and where it is?

I also have a problem with the Keyless Entry. The "Locking" button does not do anything. It clicks inside and sounds like it is locking the doors but it doesn't! The "Un-Lock" button seems to work and unlock all doors with a double click as it's suppose to. The car will un-lock and lock by itself sometimes especially in summer? It was in the body shop to fix it from hitting a deer and I think maybe they did not do something right? Any suggestions or help with these problems would be greatly appreciated!