Could you add a photo so that you can get some specific advice? In general, I would say remove the top and cut down top drawers. Then add plywood to support the seating. Upholstered cushions or directly on the plywood for the seating.
Here's an idea:
Add feet to the bottom and cut a sturdy piece of wood to fit the top for seating. Add some upholstery foam and cover with fabric. The cabinet can be painted or sanded and refinished.
Trudy: maybe this will help
This is a great project:
Please post a picture of the area, so we can see what you are working with.
see if this helps you out
Add cushions or make a slab cushion pad, by placing foam inside pillow cases! Enjoy
So fun! Is the height right for a seat?
I would buy a cushion, the At Home store sells a bunch in different sizes and then add pillows
Depending on the cupboard and how much of it sticks out you can add cushions on the lower section of it.
This tutorial might help you http://www.commatose.ca/2013/09/diy-from-old-dresser-to-pretty-vintage-bench.html
Hi Trudy, hope this gives you some ideas,
This tutorial might help: https://www.diynetwork.com/how-to/make-and-decorate/upcycling/how-to-make-a-mudroom-bench-using-old-kitchen-cabinets