We have been in a rental for a year and will be moving on.

The landlords brother helped us drill holes in the wall to hang our pictures. I dont know the name of it but in the photo below you will see that he inserted a plastic thing in the hole to enable the screw to tight.

We want to remove them all but unsure about removing the plastic thing. How easy is it to get that out?

Alternatively we can leave them all in the walls and no doubt the thieving low class money grabbing thai landlord will take money out of our bond.

With the screw a little in the plug use a claw hammer or diagonal cutters/pliers to pull it out from wall - then use wall putty to fill hole. Very easy to remove and repair hole.

Yup ^^^, that's exactly the technique I use to get the old plugs out.

Toothpaste often gets used

At the cost of above putty (42 baht or less) for a rather large container available just about anywhere really see no reason to use anything else.

you will need.

box cutter.

filler.

paint.

easy.

When in Rome leave them in the wall like the rest.