Hey everyone I’m going to replace my radiator and thought I might as well replace my core support while I’m in there since it is rusted out at the bottom. Would love to know from y’all who’ve done it, how involved it is? And any advice would be great thanks.

 

My experience is....

You'll want a second set of hands to do this.
You'll be disassembling the entire front end because the fenders have pins and wrap-around parts that sort of lock onto the core support. You might be able to just loosen the fender and get the core support out, or it may take more than that. I've only done this removing everything because that was my plan anyway.
That nut holding the passenger side down is the tough one because that side will be the most rusty. Rust penetrant is your friend here. Use it liberally several times before the big day.
One or more of the bolts holding the front of the fender liner(s) will also probably be rusted in place.
It's tricky to get the A/C coils out, but it can be done wtithout disconnecting anything.
The plastic parts can be brittle. Take it easy with them and don't overtighten fasteners when putting them back.
There are two nuts to remove behind the headlights. Use a mirror to see them. One isn't obvious just looking down into it.
If you get the replacement from a salvage yard, look closely at the passenger side as that's the side that's usually most rusty. There are some better than others so keep looking if the first one is in bad shape. Grab replacement fender liner bolts from here also if you need them.