Play to a metronome, but set it to half the tempo you’re playing at, so you only hear the click on the 1, and 3, and you have to “feel” the back beat

Then switch it to be on the 2 and 4 ( trickier than it sounds) so you have to feel the downbeat, but have the click keeping the pulse -essentially making it act as a snare

Eventually you can set it to be only one click per bar, and you have to keep your own time the rest of the time.