Change factory amp and speaker wattage.

Hi, I'm wondering if it's possible and relatively easy to change the AMP on the AS2 audio system. I've changed dash speakers and installed an extra amp for my subwoofer in the back, I've also changed the HU.

I'm also wondering if anyone knows approximately what RMS i can change the rear door speakers to if I don't upgrade amp. The new dash speakers are 50w rms and they work perfectly. Im thinking about putting 50w rms speakers in the rear door aswell but i dont know if the amp will be able to handle them.

If you have already replaced the head unit there should be no real problem with replacing the amp except that you will need one that fits in the space. Other than that it shouldn't be a problem.

Ok, thanks for the reply!