how to upgrade my haddisk? (old 2009 verion)

i would like to upgrade to 500GB+, possible?

how to? where to buy the harddisk? how to open the macmini? can i do this in Apple shop?

Thanks.

Model Name: Mac mini

Model Identifier: Macmini3,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.26 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 3 MB

Memory: 2 GB

Bus Speed: 1.07 GHz

Boot ROM Version: MM31.00AD.B00

SMC Version (system): 1.35f1

Serial Number (system): YM******9G5

Hardware UUID: 5FE145C2-5DE6-5297-B8EC-B23C4C557DB2

Hitachi HTS543216L9SA02:

Capacity: 160.04 GB (160,041,885,696 bytes)

Model: Hitachi HTS543216L9SA02

Revision: FB2AC52F

Serial Number: 091017**********1TRF

Native Command Queuing: Yes

Queue Depth: 32

Removable Media: No

Detachable Drive: No

BSD Name: disk0

Rotational Rate: 5400

Medium Type: Rotational

Bay Name: Lower

Partition Map Type: GPT (GUID Partition Table)

S.M.A.R.T. status: Verified

Volumes:

Capacity: 209.7 MB (209,715,200 bytes)

Writable: Yes

BSD Name: disk0s1

Macintosh HD:

Capacity: 159.7 GB (159,697,911,808 bytes)

Available: 24.95 GB (24,950,349,824 bytes)

Writable: Yes

File System: Journaled HFS+

BSD Name: disk0s2

Mount Point: /

<Serial Number Edited by Host>