Duplicating site without plugin

Hi. I have a wordpress site on a .ie domain that i want to duplicate on a .co.uk domain.
My process for doing this has been to back up both .ie database and files and .co.uk database and files.
I’ve then preceded to upload the .ie data onto the .co.uk domain. Next (and i’m not sure if this is right) i’ve tried to import the .ie database and then i was going to do a find a replace to update the links.
It wouldn’t let me import any new tables so i made a new database then changed the config.php file to point towards this new database and then tried to import the tables but again it wouldn’t let me.
Does anyone have any advice on what to do next?
I also tried using the duplicator plugin but that doesn’t seem to work either at there is a ‘system constraint’.
I’ve also tried to export the .xml file from the .ie and import via wordpress importer on the .co.uk but this came up with a big fail log!
thanks!