Ceiling tile may need to be replaced from time to time if their have been roof leaks or for other reasons. This a project that you can take on yourself if you research how to do it properly. Here are some basic guidelines.
First you need to select the tile you want to use and buy the appropriate amount of them. Most ceiling tiles are tongue and groove which makes them pretty simple to install.
Some tiles require you to install a metal grid and use metal clips. Two easier methods are to use an adhesive or to use nails or staples.
Some rules to follow are all cut tiles should be installed around the edges of the room. Cut tiles at opposite sides of the room should be the same size and cut tiles should never be less than half the tile wide.
If the ceiling is even, adhesive is the easiest way to go. If not use furring strips and then staple or nail the tiles in place.
Install all full size tiles first and then go aroung the edge and install the cut tiles. Once all tiles are installed complete the project with border molding.
These are just basic guidelines. Click the link below for more detailed, step by step instructions on installing tile properly.
Install Ceiling Tile