Tailight bulb replacement
 

So how do you get to the tailight bulbs to replace them? Gotta take out the whole tailiight assembly or can you do it easily from the trunk?? Thanks.

http://protege5.ugly.net/09-18.PDF page 10

Go in from the trunk. :) I'm not sure about sedans, but in my P5, there's even a little door on each side that you can access the taillights from.

Hm only if were that easy on the Protege. :(

If you can even see the bulb at all without removing the tail light then you should be able to replace it. All you have to do is turn it counter-clockwise and it pulls out .. so if you can see it or touch it whatsoever then there shouldn't be a need for removing the whole tail light.

Here's what to do on the sedan: remove the garnish around the trunk latch (take out a couple of fasteners and pull straight up). Remove another fastener on each side and gently pull the inner lining away from the trunk. Each taillight is held in with three 10 mm nuts. Remove the nuts and you can then pull gently on the taillights. There is a small locating tab on the top outside of each assembly so there will be some slight resistance when you pull on it. Once you have the assembly off you can easily replace the bulbs. FYI, here are the sizes you need:

7440
7443
194 (two each side)
7507A (this is for the turn signals, don't believe the listing at any store as all the ones I have checked are wrong)

If you forget Mazda nicely has the sizes for each location molded into the light assembly.