Do you have the quick disconnects?
If so, here's how I do it:
1. Shut off the filter.
2. Close all 4 disconnect valves.
3. Unscrew the disconnects and remove the filter from the cabinet.
4. Open top valve.
5. Open bottom valve and drain some water out into a container.
6. Close bottom valve.
7. Undo clasps and remove top of filter.
If so, here's how I do it:
1. Shut off the filter.
2. Close all 4 disconnect valves.
3. Unscrew the disconnects and remove the filter from the cabinet.
4. Open top valve.
5. Open bottom valve and drain some water out into a container.
6. Close bottom valve.
7. Undo clasps and remove top of filter.