I was told my car needs the front left wheel bearing and seal (510015) changed and both front half shafts.

Can any one explain to me how I could do this?

I'm in the process of proactively replacing the front wheel bearings and ball joints on my 1993 Civic, as we speak. It is not an easy task. Here's how to do it yourself:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-12.html#post2317484

Replacing the half-axles, however, is relatively easy.

Don't attempt this job yourself, unless you have a second car handy.

Do u know what exact parts I would need?

I bought actual Timken Front Wheel Bearings, Timken Part No. 510015, $29.87. They ended up being OEM bearings, made by Koyo of Japan.

You can buy new Cardone Select half-axles for $50 each.