Changing to a smaller gear ratio
Since it's a 1x setup you don't have to worry about the front derailleur, so it's definitely possible to swap in a smaller chainring.  That will affect your highest gear too though, so you should bear that in mind.

I don't see any reason for there to be a problem switching to a 36t chainring, noting that 36x42 is only 10% less than 40x42.  Maybe that's enough of an improvement; it's up to you to judge how much easier you need it.  It will reduce your max speed - for a given cadence - by about 10% as well in your top gear.

The SRAM X-Sync chainring has a 5-bolt, 110mm bolt-centre diameter (BCD) mounting, (sample link only) so you need to find a compatible chainring.  Again, not to make a recommendation, but a quick search found a 36t Wolf Tooth 1x chainring with a matching bolt configuration.

It is possible to find a cassette with a bigger range (though not a SRAM 11-speed) but that would require you to replace your rear derailleur as well, since the SRAM Rival 1 derailleur your bike comes with has a max of 42.  This is almost definitely not worth it.