How easy is it to remove polystyrene tiles in a house?

A survey report from the house states this:

Ceilings throughout the property appear complete and are a mixture of plasterboard construction with a plaster skim and decorative finish and lath and plaster with a decorative finish. There are no significant defects seen to ceilings, some minor cracks to the ceiling plaster in the front bedroom large bedroom.

However, to the rear lobby, there are seen to be some polystyrene tiles which are a fire hazard and these should be removed and ceiling finish made good. Where cracks are referred to, the ceilings are to be made good prior to redecoration. The ceiling finish to the covered way appears to be in an acceptable condition, small repair noted.

There are a number of ceilings with a textured coating material finish. If this material was manufactured prior to 1985, it may contain asbestos fibres and care should be taken and contractors advised if working with or near this material.

Now I have the following questions:

1. How hard is it to remove polystyrene tiles and replace them?
2. What type of professional is required to remove and replace these type of ceiling tiles?
3. It states that the tiles are to "rear" of the lobby. This means that it is only part of the ceiling that contains them?
4. How do I determine if the ceiling finish contains asbestos?