I am working on upgrading this site that has Joomla 1.5 and Old Virtuemart along with some custom code(mostly in VirtueMart). I need to upgrade this config to Joomla 2.5 and Virtuemart 2.0.24.
I searched on internet and could only find how to upgrade Joomla 1.5 to Joomla 2.5.
Please provide a series of steps that I should follow to upgrade. Also, what are the precautions that I should take and How can I keep the custom code intact.
First you will need to upgrade Joomla 1.5 to 2.5. You might consider going to 3.5 since the LTS is due out soon, but it's not totally necessary.
Once you have that upgraded, you will need to copy all of the VM tables from your old DB to the new one. Make sure to update the table prefixes so they match the new install. Once you have moved the tables, then you install VM2.0. Next, in your new VM install, go to Tools > Tools & Migration > Migration and run the migration for everything.
That's the easy part. The custom code is probably not going to be of much use to you. The entire templating system has been upgraded to work with typical Joomla overrides and the rest of the component was rewritten from scratch as a true Joomla MVC component. You will have to find all of the customization and reapply that to the new component by hand.
