If the battery blocker doesn't easily slide under the logic board, follow these steps to partially loosen the logic board from the frame:

Apply a few drops of high-concentration (90% or higher) isopropyl alcohol under the logic board to the left and right of the battery connection.

Wait one minute for the isopropyl alcohol to weaken the adhesive under the logic board.

Try to insert the battery blocker. If the logic board doesn't easily lift up, apply a few more drops of isopropyl alcohol.

This doesn't apply when using the playing card method to disconnect the battery because the playing card is only inserted between the battery connector and the battery contact pads.