I have a '98 CL with a failed CD player. The radio and cassette deck still
work fine. I have a replacement radio unit from Ebay which I would like to
install but I am uncertain about whether or not to disconnect the battery
before proceeding. I'm not sure what the risks and consequences are and I
would appreciate some informed advice.

In order to gain access to the radio I have to disconnect several electrical
dash units such as the clock, seat heater buttons, etc. plus of course
ultimately the radio itself. Is it safe to do so while the battery is still
online? If something goes wrong does it just mean a fuse will blow or is
there some risk of frying the accessory itself?

Alternatively, if I play safe and disconnect the battery then I know I will
need a radio code to re-enable any radio, which should not be a problem so
long as the codes I was provided are correct. I am also told it will reset
the ECM, which also should theoretically not be a problem as there are
currently no errors outstanding and there is no smog check is due for many
months. I am not clear tho whether I would also lose my keyless entry codes
and my 'garage door' codes or anything else. Does anyone know? Is there
anything else to be considered before disconnecting the battery?

I'd like to have a working CD player again but not if it means risking
damage to some other part(s) of the car or turning a small problem into a
big one.

TIA for any helpful advice.....