How to upgrade 2.0.20b version to the latest 2.0.22b

[akbar007]

I am using 2.0.20b in joomla 2.5 CMS. NOW I AM FACING PROBLEM in 2.0.20b VERSION LIKE MY ADD TO CART OPTION IS NOT WORKING AND CAN NOT ABLE TO ADD MORE IMAGES IN MY PRODUCT DETAILS. 

SO NOW I AM LOOKING FORWARD TO UPDATE, UPGRADE MY 2.0.20b TO 2.0.22b.

Kindly guide me how to upgrade 2.0.20b into new version 2.0.22b  with steps please..

[akbar007]

My website details are below

PHP: 5.3.27 ----  Joomla! 2.5.11 ----- DATABASE VERSION: 5.5.33-log, so can I upgrade my virtuemart version  2.0.20b to the new one  2.0.22b with this configuration..
..

Please guide me with steps how to upgrade  this 2.0.20b to the new  2.0.20b

[jenkinhill]

Download the latest file pack ( com_virtuemart.2.0.22b_extract_first.targz.zip ) from http://dev.virtuemart.net/projects/virtuemart/files

Unzip on your PC to give two components, com_virtuemart.2.0.22b.tar.gz  and  com_virtuemart.2.0.22b_ext_aio.tar.gz and use Joomla's extensions installer to install the  com_virtuemart.2.0.22b.tar.gz package followed immediately by com_virtuemart.2.0.22b_ext_aio.tar.gz

Updating a VM version is unlikely to fix an add to cart error which is usually caused by something in the Joomla template.