Go to a parts store and get replacement pins. You can probably use generic ones, but it is probably best to have them pull out the ones that are matched to your Blazer.
Then you can either
1) Try to replace the pins one at a time by hammering one out and replacing it and then doing the other OR
http://www.2carpros.com/forum/door-hinges-on-a-1996-chevy-blazer-vt19820.html
2) Remove the spring with a tool (with a little luck autozone might rent one to you) and replace both pins at the same time. The following tutorial with loads of pictures is really helpful:
http://www.bodyshopzone.com/archives/mechanical/door/hinge/pin_replace_1.html ond these guys http://www.s10forum.com/node/36
Sometimes the holes in the door or the hinge have started to get worn into an oval / egg shape. When this happens, you have to repair the hole somehow. Some suggest that filling the hole with epoxy might work. Generally it is recommended that you weld and re-drill. Chances are you'll have to have someone do it if this is needed. If the bushing just wore out recently, replace pins and busings and you're done. Good luck!
Remove the fuel tank for access
Replace and bleed line
No, You will have to remove the fuel tank.
Your 1999 Chevy blazer doesn't have a timing belt.
Will a 1997 blazer what work on a 1999 blazer????? If your talking engine, transmission, or running gear than yes. It is all the same.
Service brakes - replace Master cylinder Parking brake- either lubricate or replace cables ; I had a similar problem with my 1999 Chevy blazer, i ended up replacing the caliper and have had no problems since.
sounds like you need to replace hinge pins.you can purchase replacement pins at any auto store
Check related answers. There are several responses and are quite accurate.
How to change the bulbs in the climate control for a 1999 Chevy trailblazer
Mostly, yes.
how to drai torque converter on 1999 chevy blazer
These are low voltage sensitive. .Replace your car battery.