I replaced two of those on my previous coach, at 2002 Journey. Use a 1/4" nut driver to release the pressure on the solenoid (open 2 - 3 turns). Disconnect the two wire connector going to the solenoid. I used a pair of channel lock pliers to loosen the solenoid, then it came out easily. Just make sure you keep everything as clean as you can so as not to introduce dirt in the system.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
Glen Allen, VA; Smith Mountain Lake, VA.