I have a Trek Fuel EX9 29 2016. Its a SRAM 1x11 X-Sync, 32T in front, 10-42T in the back. My rear hub is boost-148. I want to replace the 32T with a 26T. Can someone recommend specific models I can buy? I tried searching online, but just get confused with all these terms like (direct mount, spider, offset, chainline, one-up, etc)?

Wheels: 29"
Rear Hub: Boost-148
Shifters: SRAM X1, 11 speed
Rear derailleur: SRAM X1, Type 2
Crank: SRAM X1, 32T X-Sync (want to change to 26T)
Bottom bracket: PF92
Cassette: SRAM XG-1150, 10-42, 11 speed
Chain: SRAM PC 1130