Then I push a cheap screwdriver down the nozzle to puncture the inner seal. I press the foam firmly against the MDF panel. This has the effect of smearing adhesive on the MDF panel, too. Then I pull the foam away and let it lie flat on the floor. That adhesive stinks, by the way.
Good ventilation is recommended.
While it's having its 5-10 minutes, I clean off the cheap screwdriver with a paper towel. It's had its 5-10 minutes. I manage to avoid the ceiling-mounted track lighting. I now press and push the foam piece firmly, all around, into a tight position in the corner. Although it seems to stick firmly, I use the step ladder to weight it firmly against the wall.