Hi,
You're doing as much as can be expected to safeguard yourself in the event of anything untoward happening when removing the battery etc.
The only thing that you haven't mentioned doing is responsibly disposing of the faulty battery. ;-)
Here's the [http://h10032.www1.hp.com/ctg/Manual/c06358101.pdf|maintenance and service guide] for the laptop.
Go to p.49 to view the procedure to remove/replace the battery.
Also at the top of the page you will find the part number for the battery. Search online using the ''part number only'' to find suppliers that suit you best