I tried to do a search for about 5 minutes, so I did my due diligence. 
I have a Quarq Cinco, 110mm BCD 50/34 with the same SRAM chain rings that it came with. I still have the box that has the sticker with the slope reading on it, though not with me at the moment. I want to change to 52/36 rings, and already purchased what looks to be the exact same model line of chain rings. SRAM/Truvativ Red/Force/Rival Apex 36T and SRAM Red/Force 52T. I’m just stating exactly what is printed on the label.
I’ve searched other posts and they mentioned that SRAM has an online table for slope changes to other sized chain rings that they already tested.
http://www.quarq.com/ring-difference
However, that link seems like it’s no longer working. Does anyone know if that table had the information about the slope differences between my current setup and what I’m trying to go to? And if so, does anyone still know what the slope change would be? I’m just trying to see if I can avoid the step of obtaining or verifying a known weight and going through the actual calibration process myself.