Nelliemoser. If you have a zip fly, you don't need to drop the trousers. Otherwise you would have to pull the waist band down just at the front to enable inserion of the Shewee. The manufacturers recommend practicing in the shower first!. There is always an anxious moment before the stream appears! Being silicone it drains well, obviously it must point downwards! An extension tube is available for when you have on several layers and want to ensure clearance. The advantage as opposed to squatting is, as for men, one can stand behind or against a tree, for instance.
I well remember a moorland comfort stop on an HF holiday, seeing a row of bare female bottoms amidst the heather in full view of both sexes! I wouldn't be able to go in those circumstances!
Good luck if you are brave enough to give one a try!