Use the SRT-6 as a lever to release the snap. Do not twist SRT-6, because this would damage the cover.

Now release the next snap. Use the same procedure on the other side.

Remove the modules from the B-Cover.

Place the SRT-6 between the Engine Module and the UI Support Frame. To open the connector, twist it carefully as shown in the picture.
Now, the Engine Module can be removed.
Special Thanks
ALLAH SWT, Blogger.com, Forum Djawir, Komonitas Tekhnisi Ponsel Indonesia, EL-EM Foundation.