Engine loses power. Replacing plugs?

I have a 2000 Astro that has been sputtering and losing power whenever the weather seems to be cold and/or damp. It almost seems that the transmission is slipping but I've had that checked and the mechanic said the trans is o.k. Once the engine warms up it runs fine. Recently the SES light came on. I took it to Autozone and the code was for cylinder 1 misfire. I checked the spark plug wiring last night and they appear to be fine.

I guess I will check the plugs next. Can anyone tell me if there is an easy way to get out the spark plugs? Do I need a special tool?

Has anyone else experienced this problem?

Thanks

How many miles on the plugs, also may be easier to access from the bottom.

62k on the original plugs

could be anything for the loss of your power, old spark Plugs, air filter "dirty" bad fuel pump or Bad compression on one or few of your cylinders.

I know mine is going big time. The engine has been over worked with 3500 lbs worth of cargo and over 520.000.00 KM on it? the engine is going and i am losing the battle with Cyl number 4 as it is no longer a combustion chamber, but an Auxilary oil Pump. LMAO.

PS: i have one question, how can you tell if the Engine is a Vortec? as i am having my engine rebuild, and my cover says vortec on it, but most mechanics are in doubt about it, any other way to find out if it is really a Vortec engine 4.3 v6?

Thanks

if your eigth digit in your vin is a z then it is non vortec and if the digit is a w then it is a vortec, also look at the engine with the cover off and look at the top of the engine, vortec has seperate injectors as a non vortec does not
scott.
ps. my 94 astro does say vortec on the valve covers but is not a vortec. just a way to use up extra parts at the factory.