I have an SA Scout Squad in a Sage EBR chassis.

Is there available any sort of step by step procedure for this that's recommended here? I've had this beast for months and have been meaning to get to know it inside and out, but I know it isn't as easy as an AR. I'd like to break it down and clean it before using it again.

Also, I know that it needs to be cleaned with grease, rather than oil. What kind of grease should I get for it?

I don't know of any published guides.  One has two options, 1) "cleaning" of the rifle assembled, or 2) actually cleaning everything by taking the gun out of the chassis and cleaning everything (I would not want to do this in the field {fear of lost screws}).  Hope that clears things up.

I suppose what I mean is detaching the bolt from the rifle so I can clean that out.

I know the rifle has a piston, and it doesn't get dirty as often as a result, but still. Every guy should know their tools inside out.

Remove the magazine and Clear the rifle, loaded guns kill more people during cleaning than unloaded ones.
Remove any optics mounted to the rifle.
If the SAGE stock has the wrap around Kydex handguard remove the three screws securing it to the stock and remove it.
Remove the screws securing the top handguard in place and pull it away from the stock.
Three cap screws bolt the stock to the operating rod guide, remove them and remove the trigger housing by pulling down on the trigger guard to unlatch it.
This is best accomplished with the rifle in a cocked position and the safety in the "ON" position though pulling the trigger guard down will also cock the action to allow for removal of the trigger housing.
Once the housing is free, remove the barrelled action by turning the rifle upside down and thumping on the top of the stock housing.
The action will seperate after you have put a pretty good bruise on your hand from the thumping.
Remove the operating rod spring and guide by pulling the guide back towards the muzzle and sliding the connector lock free.
The connector lock looks like a free standing roll pin, which it is, push it or hammer it to the side depending on how carbon/rust fouled it is.
This is best accomplished with an 8 pound shop hammer and a machine punch. (Just Kidding!)
Lift the spring guide up and pull it and the op rod spring out of the op rod tunnel and off the rifle.

Assuming your rifle is a semi auto M1A type rifle, pull the operating rod full to the rear until the tab on the op rod lines up with the takedown notch.
Pull the op rod handle up and out, away from the receiver while wiggling at the same time and it should pop free from the receiver.
If it doesn't do so fairly easy, ha-ha, you have a rifle with a misdimensioned op rod or receiver, take it to a gunsmith before you damage the rifle or hurt yourself.
If it does pop free, carefully manipulate the op rod to clear the op rod guide on the barrel and then pull it back and out to free it from the receiver.
Align the bolt so it is half visible in the ejection port, lift the front of the bolt up while pulling to the right and wiggling, just like the op rod. It should come out of the receiver.
If it doesn't do so fairly easy, ha-ha again!
This completes a basic field strip of the SAGE stocked M14 type rifle.HTH

Makes reassembly sound like a bitch

Nah.
"Reassemble in reverse order."