Exhaust Manifolds

[dmc_delorean_2000@xxxx]

hi Guys
its me again, i might be getting annyoing, but i have no where else 
to turn for advise, nobody where i live knows what a DeLorean is. my 
pass side exhaust manifold is cracked so i bought a used one in good 
shape (new is too expensive), but when PJ Grady had my car in 
january, he told me it was a big job (he wanted $800 to do it). now 
as some of you know i've had a lot of problems with mechanics so im 
taking some of your advice to do the work myself. my question is how 
shold i go about this? is it that big of a job that i should just let 
a mechanic do it, or do you think me being an amature can do it? if i 
do the work myself, what am i getting into? any info would be very 
usefull. plus i've got a whole bunch more question but i'll wait for 
my car to come back before i flood the message board.
Thanks all
Tony