I have the HP Envy 15-as020nr. When trying to use the computer types the letter w on its own even if the keys are not sticky. It is dirty underneath the keys and I've tried cleaning them to my best of ability to no avail. And I'm hoping it's just dust that needs to be clean. However I can't dismantle the keyboard to remove it completely. If cleaning doesn't work I wanted to replace it. However I'm unsure how to safely remove the keyboard without damaging any other parts.