All laptop companies issue a service manual for each model which includes full disassembly details. This is the manual used by hardware technicians working with the laptop. This is distinct from the user manual, which is what the user gets, and which is a lot less technical in nature.
I've searched for and found the service manual for my laptops online, but not without going to some trouble. If you're lucky, you might find a site that gives you the service manual for free, else you might have to shell out a small fee.
If you can find the service manual for your model, that would be the preferred way as you'll be following the HP-approved way to open up the laptop.
If you can't find the exact service manual you need, do a bit of research on these:
- The same laptop often has a completely different name in a different market. I couldn't find the service manual for my Acer Travelmate model sold in UK/Europe, but the same laptop is marketed in the US under a different line, and I found the service manual for that.
- A number of laptops of the same family have the same shell/body, and consequently the same instructions to open them up. If you can find other HP laptops belonging to the same family as yours, search for their service manuals.
If you can't find anything at all to help you, play it by ear and be careful when you open up the laptop. Make sure you have the right tools.