Maryland Gun Works makes a very nice rear sight pusher tool that costs about $100.
Ed Brown makes a front sight tool that runs around $20.
You can get a less expensive sight pusher on eBay for $39.95 (free shipping) from a seller named 4x4machineshop. This works on the Glock, 1911, and most pistols with straight sides. They have another model that includes shims for pistols with angled sides for $49.95. I have used this tool to install sights on my Glock and it works well. You will need a wrench to turn the bolt. This tool is also handy for adjusting your sights at the range.
You can make your own front sight tool for the Glock. Just get a 3/16" 6 point 1/4" drive deep socket ($2.97 from Lowes). You will have to use a bench grinder to make it work. The front site screw is very close to the front of the slide and the socket is too fat to clear the space. Grind away the circumference of the body of the socket until it will fit. Also, the screw head is very low profile. You fill have to flatten the the end of the socket, because the rounded edges won't let it grip the screw. You also need to taper the end a bit.
You will also need a triangular file for fitting of the rear sight to the dovetail. You can pick one of these up for under $5. I won't go into the process of how you change out the sights. There are plenty of resources on the internet for that.