Force close a channel that has left a triangle swap (8762)

Gator previously asked the following question:  I am a member of Triangle Swap # 8762. One of the members (RidetheFreakingLightning) has been offline for around 70 days. The other two of us (dmzNode and Gator) are unsure of how to proceed.  
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From DMZNode:
Previous response indicated to force close this channel for safety, but I'm not sure how to force close a channel on lightning swap.
I believe I can force close the channel via the umbrel,  "Ride The Lightning "app but after looking I don't see them even connected.  So they must be closed but if there is something I can do via the Triangle swap lightning channel please let me know and I'll do that.  

thanks,