Nissan Repair: coolant leak from plug on block, coolant leak, radiator cap

Question
have 1990 nissan truck with 2.4 liter engine,just finished replacing the radiator,thermostat,and radiator cap.Started engine and ran till at normal temperature, everything seemed ok coolant flowed, radiator was hot throughout the coils.Now a small amount of coolant is leaking from one of the plugs on the exhaust side of the block on the back side of the engine,it is not the threaded bolt.Can this be replaced by myself or should i have someone else do this? Thanks for your help!

Answer
Glenn,

If this is a freeze plug or Welch plug it is just a matter of driving it in and then getting vice grips and pulling it out and then driving a new one in with a socket of corrisponding size, as not to damage the new one.  Use sealant on the new one and get it flush like the old one.  If you have to take items off to access it then so be it.  Otherwise you could take it to a shop.  But, the fact is, it is a pretty easy job if you take your time.  Now, if one is rusted out and leaking then the others are not far behind.  So, you migth replace them all.