Migrate one Wordpress website to another

Requirements

There are 2 wordpress installations. Once the old, from which the data should be transferred, and a new empty Wordpress installation.

Make sure that the access rights and the owners are correct. 

Folders should always have a permission of 755. Files from 644. (Commands below: find all directories (d) / files (f) from here and execute a chmod 755 / 644 on them).

find . -type d -exec chmod 755 {} \;

find . -type f -exec chmod 644 {} \;

Step 1: Install All-in-one WP Migration

Make sure you install and activate the right plugin on both Wordpress sites.

Step 2: Export the data from the old Wordpress

• After installing the plugin, select the sub-item "All-in-One WP Migration" in the menu and click "Export". There you will be given a choice of export options. To save the file on the PC, click on "File". Now the export starts.
• Now you have a file with the extension ".wpress". 

Step 3: Import the Data into the new Wordpress

• If the file upload size is too small, increase it manually. It is important to do this without a plugin. Because you can't have a plugin enabled to start the import.
• First, make sure that you do not have any plugins active on the target WordPress site. Otherwise the import will not work.
• Select the sub-item "All-in-One WP Migration" in the menu and click on "Import". There you will get a "drag and drop" area. Simply drag the export file into it and the import will start.
• After importing, you will see a message telling you that the import was successful and asking you to save the permalink structure twice. Just follow the link and press save twice. 

Finish!

You have successfully migrated a wordpress site to another site