Can I replace laptop SSD harddrive with normal drive without voiding the warranty?

I have a Thinkpad w510 with a 128 GB SSD drive. However, I have found out that storage capacity of the SSD disc is insufficient.

My question is: Is it possible to a get new laptop 500 GB harddrive and can I replace it without voiding the computer's warranty.

Yes, you can replace the disk without voiding the warranty. For instructions on how to do it, see T510 HW manual. Also, see the pictures in this answer, T510 drive bay

However, as MicTech says, your should consider putting the 500GB disc in the Ultra Bay with an adapter, e.g. see Ultra Bay HDD adapter. This way you can have the OS on the SSD (fast boot etc.) and have capacity demanding data on the slower but larger 500GB disc.

Yes, you can replace it yourself. Look on the underside of the laptop and look for the harddrive compartment. Unscrew the screws and lift the lid and you'll see your SSD harddrive in there. Just replace it with a normal 2.5" harddrive and all should be ok. It's quite easy so give it a try.

It's possible, because SSD drive have SATA interface and possibly same size like standart mechanical 2,5" HDD.

This is OK for ThinkPads, you don't worry about warranty.

or

ThinkPad w510 has Ultrabay III, where you can connect adapter for HDD, which can take any 2.5" HDD.

UPDATE: There is no limitation for size, basically. Limitation is size of HDD.