I had recently replaced the batteries in one of my Maglite's (about a year ago), well as usual the batteries swelled up and started to leak, of course due to the crappy design of these flashlights it is near impossible to remove the batteries in this situation.
I tried dropping the flashlight open side down on to a throw rug on tile. While it did move the batteries down to the end of the battery It bent the very soft aluminum. I then tried to pry the batteries out but that just bent the flashlight the other way.
I did some googleing and did not find much information on getting the batteries out. I did find that Maglite's attitude is "too bad for you". But I did manage to get the batteries out. Here is how:
First remove the lens assembly.
Remove the light bulb.
Remove the plastic part labeled "DO NOT REMOVE". It just pulls right off.
using a thin screw driver placed in one or both of the holes you see above. Push down or if needed lightly hammer the batteries out. DO NOT hammer directly on the plastic switch. The switch assembly will push all the way through the tube. Once you get the batteries out (if you get them out). You will need to clean out the tube. Use a small file, a hone, brass bottle brush, or whatever you can find that will work. Rinse out the tube and thoroughly dry it. Check that the silver tab is clean, then push the switch assembly back in place as you see it above. Replace the part marked "DO NOT REMOVE". Install the bulb and clean it off with alcohol. Reassemble the rest of the flashlight with new batteries.
VOILA!