I have 98 Chevy Malibu Ls V6 and it seems to be leaking coolant from the bottom of the coolant recovery tank, the low coolant light comes on and stays on for a couple of miles then goes off so ill pull over and add a little bit of coolant and then the light will stay off for about a month and then it happens again. There is what looks like a rubber plug on the bottom of the recovery tank that seems to be the problem and it looks like that is were the coolant is coming from, any help would be great, I can not afford a mechanic at the moment. Right now the car is not over heating but I don't want to just let it go and have something major happen, please help.

Either replace the tank, or keep topping it off until you can get it to a shop.

If I replace the tank, Do I need to completely drain the radiator? if so how much coolant do I put in when I am done?

What you can do is remove the tank(disconnect the two hoses, and remove the screws holding it to the body, remove coolant sensor harness).....pour what is left in a container to be reused........then look on the under side for a crack.....there are numerous epoxy sealers that you can buy to repair the crack, which looks like a hairline crack.......or, you can go to a junkyard and get a replacement....

No, you do not have to drain the radiator....

If you look at the seam in the middle of the tank, just below the cap, you will see a "cold level" line.....so fill the reservoir to that line.....put cap on reservoir and run car to normal operating temp.....with expansion, the level should slightly rise in the tank.....

Check the level the next day when cold, and add to the line if necessary....