Skill/spirit gem downgrade

Can we get a way to downgrade these gems please? We drop lots of 18/19 and if you want try something new but need lvl 14 due to attribute req you have to trade or do low tier maps that we probably don't have so again trade for maps.
Unless I am not aware please educate me.


Thanks

It's going to be T1 maps or trade, those will be your options.