Help me DIY my old corroded brakes!!

[1993CivicVX]

I have a '93 Civic VX which I just bought. 175K miles. No squeaking or anything.

My friend and I just removed the rear drum to replace shoes and hardware after my mechanic told me I need new rear brakes.

Much to our horror, the innards of the rear brake system look like they have never been touched in the life of the car. The piston looks very corroded, and only one shoe moves when brake is applied.

The inner lip of the "housing," (not sure what this is actually called) is cracked in some places, looks like water can easily come in. Does this need to be replaced?
Does the piston need to be replaced?

In any case, the shop forgot to give us the hardware kit, so we couldn't do the job.

We're now wondering whether or not to let the mechanic do the entire job. He quoted my friend $475 to do the back brakes and fix the ebrake with two new cables, but we're not sure if his quote included replacing the piston and the housing.

If it's easy enough to replace the entire housing and pistons, we'd probably do it ourselves.

My friend has experience in just replacing shoes and hardware, which he is now pretty good at, but feels the other things are beyond his reach.
Could this be learned relatively easily?

Here's a link to pictures we just took of the brakes.


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The question is do I return all the hardware I just bought or do I buy the rest and try to do the job ourselves?

Thanks Jake and Ben.