I bought this tool as I struggled to get the wipers off too. Just ensure you get a large flat head screwdriver under where the rounded part of the tool sits on top of the thread as it kept slipping off when I did it. Reason to this is because the shape of tool when it is on the wiper arm, the two "legs" underneath don't quite stay where they should be when winding the top part down. But it's really worth getting one. Just use something to stop it slipping off.
Once both wiper arms are off you can remove scuttle panel. I removed both sections and gave it a good clean underneath. Then you remove the three bolts holding the wiper mechanism in place, get your hand underneath and feel for the little peg that the wiper mechanism locates itself on. This is crucial! Once you remove the mechanism you can access the washer bottle.
The leak I had was that the pump had just come loose and away from the bottle so it didn't hold any water. I also had to Trim the little cylinder down inside the pump.
There is a guide to do all the above.
It's not too difficult. And doesn't take too long. I would really consider getting a wiper arm puller off eBay though.
Hope this helps
Chris