1985 300CD-T (Calif.): Removing original block heater element

[5cylinder]

My vehicle is a 1985 300CD-T (California).

Issue:
I am seeking to remove and replace the original block heater element.

Question:
What, if any, issues/trouble are/is there with reaching the block heater element given the infamous trap oxidizer on this vehicle?

I intend to soak the old element with PB Blaster off and on for a couple of days prior to undertaking the job in an effort to perhaps ease removal.

Thanks for any advice or comments about this work.