Hi @nikhilgawande
Here's the [https://www.levnapc.cz/ProductsFiles/nc6220-servisni-manual.pdf|maintenance and service guide] for the laptop. Go to Sect.6-48 (p.150 of 226 pdf) in the guide to view the procedure to remove the systemboard. This will allow you to install the speakers.
Search online for [https://www.google.com/search?client=firefox-b-d&q=hp+5H82|HP 5H82] to find suppliers of the speakers that suit you best. (examples only)