Can I move a master Tivo DVR hard drive to another unit as a slave second drive?

[Iluv2watch]

I have 2 TVs, each using a R10(80Gb). I just purchase 2, HR10-250 from ebay. So now I have 4 boxes.

One of the HR10-250 cannot be activate because of overdue fees.
Can I pull the master hard drive from one R10, add it to the other R10 unit, with a bracket, cable, and change the IDE switch from master to slave, and with no software changes, will it work?
Is it a IDE hard drive?

And do the same on the HR10-250:
Can I pull the master hard drive from one HR10-250, add it to the other HR10-250 unit, with a bracket, cable, and change the IDE switch from master to slave, and with no software changes, will it work?
Is it a IDE hard drive?

Or another option:
Can I take the HR10-250’s 250Gb drive and add it to the R10, and make the 250Gb the second slave drive?

My issue is I don’t know anything about Unix/Linux and am afraid of opening my computer and connecting these drives to update their software. So, I am hoping I don’t have to do any software changes but only do a jumper change from master to slave. May sound stupid, but thanks