If your timing chain is very rattly, then it maybe the chain tensioner, although chains do stretch a bit.
I personally would not bother unless it is VERY noisy, old and prone to failure but failure of the chain is quite rare.
I don't know if you can get at the chain cover without removing the front radiator panel, I suspect not.
If that is the case then you will have to remove the bumper and radiator (with the front panel), also the fanbelt, front crank pulley and timing chain cover.
You will need a special long socket for the crank pulley bolt (which takes the starting handle).
While you are at it you may as well replace the front crank oil seal, and you will need a new gasket for the timing cover.
The cam and crank gears have marks to line up for when you put the new chain on. As long as these are lined up you should not "blow up your engine".
I would advise not doing this job as it is really not worth the hassle, if the chain is worn and old, then the chances are that the engine is also and so may need a 'freshen up'. Replacing the chain is usually a job that is done when an engine is re-conditioned, although if you are hell-bent on changing it then of course it can be done, although it is a lot of hassle.
If you have a Haynes manual then look it up in there to give you an idea, if you have not got one, then get one! It is a good investment - Try eBay I got mine for a coulple of quid.
Good luck!
Cam.
