the method for removing drums differs from track to track but as a general guide this is what I do (this is assuming that you don't care about any existing bass instruments or sub bass):
1. filtering, use a high pass filter to cut out everything up to around 400Hz with a slight amount of resonance, the resonance makes sure that any other instrument close to 400Hz aren't affected.
2. EQ, with an EQ make a slight 0.2-3db cut anywhere from 1.8kHz-3kHz with a wide Q, this just helps to tame the high end of any kicks or snare a little bit making them more subtle, obviously if its affecting the sound you want then ignore this step.
3. Reverb, This is a step where personal preference is key, a reverb with a long decay time and the Dry/Wet set to mostly Dry will have a subtle effect but it can work wonders to help mask high hats and the high end of kicks and snares, this trick wont always work and can reduce power in some instruments but when it does work it can make even the most pronounced drums seem to fade from of the track.
4. side-chain, there are 2 options when it comes to side-chaining, you can either use side-chain compression to duck the volume of the track when your drums come in or you can use side-chain Eq to duck specific frequencies when your drums come in. the second option is more subtle and has less of an effect on other instruments but it might not do enough to hide the drums.
5. expand/gate, once you've applied the previous steps the volume of the drums should be significantly reduced which makes them the perfect target for an expander or a gate, with this step its a simple case of slowly increasing the threshold until you have the desired effect, this step should get rid of any remaining drums that you no longer want (emphasis on the word "should" there because it doesn't always work in the way you want it to)
These steps should help you cut out those difficult to mask drums but they are by no means 'perfect' solutions, they don't always work but they can help. also you might not need to use all of these steps or necessarily use them in the order shown above, like i said it differs from track to track
hope this helps anyone that struggles to remove drums
