There are a couple possibilities for this:
1. Is the mutli tool oriented correctly within the EDC tool body? If it is backward and not meshing will the tire lever, the tool will bulge and be difficult to remove
2. The multi tool side plate bolts have loosened off and are jamming against the top cap.
For both situations the solution is to: 1. Loosen the stem bolts
2. Using soft jaw pliers, or pliers with a cloth, loosen off the top cap.
3. pull the top cap and tool off the steerer tube.
4. Either remove the multitool, or tighten the side plate bolts. The tool will then slide out of the top cap and you can reassemble everything correctly.
Please email support@oneupcomponents.com if you have any trouble with this process, or damage anything, and we will be happy to help.