What is the procedure for flat towing behind a Class C. I'm relatively new to both the Hummer and the
RV.

 

You can download a free owners manual from GM for the HUMMER H3 that will explain the exact process for flat towing.

I hope this link works:
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.gmc.com/ownercenter/content/dam/gmownercenter/gmna/dynamic/manuals/2007/hummer/h3/2007_hummer_h3_getknow.pdf

 

Welcome to HF.

Take a read through your Owner's Manual........... there is a reason each H3 was sold with one in the glove box, and they are on line free for the viewing.

Take a read through the many threads here about Dingy Towing and H3. This one might be harder to find, but it has all the info. Use existing front tow hooks to hook to “Blue Ox” or similar systems

 

Thanks. This is what I found and it's not super clear.

Dinghy Towing Use the following procedure to tow your vehicle: 1. Shift the transmission to NEUTRAL (N). 2. Turn the engine off, but leave the ignition in ON. 3. Firmly set the parking brake. 4. Securely attach the vehicle being towed to the tow vehicle. {CAUTION: Shifting a full-time four-wheel-drive vehicle’s transfer case into NEUTRAL can cause your vehicle to roll even if the automatic transmission is in PARK (P) or the manual transmission is in any gear. You or others could be injured. Make sure the parking brake is firmly set before you shift the transfer case to NEUTRAL. 5. Shift the transfer case to NEUTRAL (N). See Full-Time Four-Wheel Drive on page 111 for the proper procedure to select the NEUTRAL position for your vehicle. 6. Put the transmission in PARK (P) for an automatic transmission or in FIRST (1) for a manual transmission. 7. Release the parking brake only after the vehicle being towed is firmly attached to the towing vehicle. 8. Turn the ignition off. After towing, see “Shifting Out of NEUTRAL” under Full-Time Four-Wheel Drive on page 111.

 

What's not clear? Discounting the actual hook-up to your tow vehicle/RV, in order to tow your H3 you simply need the Transfer Case in Neutral (instructions in the manual); and the Transmission in First (since yours is a manual). Obviously with the truck in neutral (TC or Trans) it will roll, so you need to use the parking brake if you aren't already hooked up to your tow vehicle.