Remove inner sill covers
To remove rear inner sill cover, first remove one plastic clip, then simply pull the cover upwards.
Rear inner sill cover removed. You probably will end up with 4 plastic clips disconnected from the trim and left in the metal under the cover. Remove the clips one by one...
... and put them back in the still cover.
Repeat the same for the front still trim cover.
Now remove B-pillar trim. Pull the bottom part towards middle of the car. This will release two plastic clips. Once bottom part is loose, slide the trim downwards to disconnect the top part.
B-pillar trim removed.
Remove the same trims from other side of the car.