Those instructions you link to are fine, but are given for a specific type of brake caliper which may not be the same as your vehicle's.
What vehicle are you working on? Designs can vary a lot.
The C clamp for compressing pistons only works if you have clearance to put the clamp in place. Otherwise you'll probably need a purpose-made tool.
In my experience, the L-shaped lever type works quite well within its limits: insert the blade of the tool, twist the handle to move the piston. The width of the blade limits the extent to which the piston will move. My tool is made by Girling; I'm not sure if they still list it.
Sykes Pickavant (and others) make a tool with two plates; one bears against the caliper, the other against the piston. Winding the handle turns a screw which forces the plates apart. If you have a stubborn piston, the plates can bend without the piston budging.
A better tool is an air-powered piston compressor; an air-powered ram is used to push the caliper piston. To use one of these you may need adaptors to fit your calipers. And of course you'll need an air compressor, so not really a recommended course of action if you're just starting.
Be aware that some pistons have to be turned while they are being pushed; for this, you will definitely need special tooling appropriate to your brakes.
One thing your on-line instructions don't mention is the need to loosen the bleed screw to allow fluid out directly. It's possible to damage ABS components if you don't do this properly. And of course, retighten and top up fluid levels when you've finished.
I recommend getting the Haynes Brake Manual which has fairly good coverage of a number of different braking systems, and plenty of sound general advice. After all, you want to be sure that you've done everything properly and that the brakes will work when you put the car back on the road.
What vehicle are you working on? Designs can vary a lot.
The C clamp for compressing pistons only works if you have clearance to put the clamp in place. Otherwise you'll probably need a purpose-made tool.
In my experience, the L-shaped lever type works quite well within its limits: insert the blade of the tool, twist the handle to move the piston. The width of the blade limits the extent to which the piston will move. My tool is made by Girling; I'm not sure if they still list it.
Sykes Pickavant (and others) make a tool with two plates; one bears against the caliper, the other against the piston. Winding the handle turns a screw which forces the plates apart. If you have a stubborn piston, the plates can bend without the piston budging.
A better tool is an air-powered piston compressor; an air-powered ram is used to push the caliper piston. To use one of these you may need adaptors to fit your calipers. And of course you'll need an air compressor, so not really a recommended course of action if you're just starting.
Be aware that some pistons have to be turned while they are being pushed; for this, you will definitely need special tooling appropriate to your brakes.
One thing your on-line instructions don't mention is the need to loosen the bleed screw to allow fluid out directly. It's possible to damage ABS components if you don't do this properly. And of course, retighten and top up fluid levels when you've finished.
I recommend getting the Haynes Brake Manual which has fairly good coverage of a number of different braking systems, and plenty of sound general advice. After all, you want to be sure that you've done everything properly and that the brakes will work when you put the car back on the road.