Engine change

Hi guys, is it fairly straightforward on the k12 to take engine out? Whats easier, complete with box?

My wifes 1.2 auto is getting lumpy and grumpy although not bad when warmed. so I was thinking either swap her out for better engine or sell it and change car completely

Theres plenty of engines on ebay about £250, low mileage and later models. Ideally id upgrade to 1.4 for few bhp to offset the sap of the auto box bit most 1.4s for sale are from manual cars. Is it best to get one already from an auto for simple bolt in conveinience or is it easy to swap over flywheel if I got engine from a manual to fit to her auto box?

Any tips or suggeations welcome. Thanks
Can't answer with absolute certainty, but I'd assume that all cr engines bolt up the same way so in theory it'd be a straight swap (ecu may need changing)