How to upgrade M2E Pro on Magento Marketplace? [for Magento v 1.x]

 * If your M2E Pro was initially installed via Magento Connect Manager, please complete the following actions first:

1. Log into Magento Connect Manager in your Magento backend (System > Magento Connect > Magento Connect Manager).

2. Find M2E Pro Extension under the Manage Existing Extensions section. Uninstall the Module.

Note, the Uninstall action applied just removes the code of old M2E Pro version. It does not affect your existing M2E Pro configurations. All M2E Pro Listings, Policies, etc., which you have previously created, will be saved.

3. Install an Extension via Magento Marketplace.

The latest Module version, including your existing M2E Pro data, will be installed from Magento Marketplace. The future M2E Pro upgrades via Magento Marketplace should be performed according to this instruction without any additional actions required. 

 * If your M2E Pro was initially installed via Installation Tool / Manual method, please complete the following actions first:

1. Log into Magento Connect Manager in your Magento backend (System > Magento Connect > Magento Connect Manager).

2. Check an Extension list under the Manage Existing Extensions section to ensure that M2E Pro Extension has not been previously installed via Connect Manager.

Note, if M2E Pro is on the list, you must proceed with the instruction above.

3. Remove the following files/directories in your Magento file system:

'app/code/community/Ess/M2ePro',

'app/design/adminhtml/default/default/layout/M2ePro.xml',

'app/design/adminhtml/default/default/template/M2ePro',

'app/etc/modules/Ess_M2ePro.xml',

'js/M2ePro',

'skin/adminhtml/default/default/M2ePro',

'skin/adminhtml/default/enterprise/M2ePro'

Note, only the code of old M2E Pro version is removed. This action does not affect your existing M2E Pro configurations. All M2E Pro Listings, Policies, etc., which you have previously created, will be saved.

4. Clear browser (CTRL+ F5), Magento and all 3rd party extensions caches. If OPCode is used, it should be also cleared.

5. Install an Extension via Magento Marketplace

The latest Module version, including your existing M2E Pro data, will be installed from Magento Marketplace. The future M2E Pro upgrades via Magento Marketplace should be performed according to this instruction without any additional actions required.