I worked on this extensively over the summer.
The short answer seems to be that it is not possible.
Some folks claim (CLAIM...) that other functions run through this battery and they have had strange behaviours after disconnecting and removing it. I can state that I left the battery in place after it went dead and had no problems other than the idiot light shining in my eyes, but I grew concerned about leakage.
In the end, and because it is my daughters truck, and she is 1500 miles away and I didn't want any problems, I replaced the battery. It's an easy job. It is located on the drivers side - remove the cover closest to the firewall and it's easily accessible.
I have the specifications elsewhere on this forum, but it's an Exide EK151 - perfect OEM match, no messing about with new connections or cables.
The least expensive option I found was to purchase from
Groves Batteries, Cheltenham, UK.
They ship to the US, the delivery was super fast and they are super easy to work with.
Even though the shipping cost was crazy expensive, it still turned out $100US less expensive than purchasing in the US.