How to disconnect/unplug engine & light harnesses from firewall block

[77thor]

Ok, I'm in the middle of a under-dash wiring harness replacement using American Autowire 'Factory Fit' harness...
How do you remove/unplug the lighting & engine harnesses from the firewall side of the fuse panel??
I removed the center bolt from the firewall side and also removed the 2 inside screws holding the fuse panel.
But I still can't budge them... Is it just 50 years of gunk holding them in? or did they apply some sealant at the factory? 

I'm worried about prying on them and possibly breaking the connector.

[Kelley W King]

It is not gunk. They used some tar like sealer that works really well. Never tried it but a heat gun might help.

[77thor]

The other problem is, the brake booster is in the way and I can barely get my hands on the connectors.

[77thor]

Got it.

[firstgenaddict]

It is easier to leave the two screws that hold the fuse box to the firewall in when unplugging.