Hi. I'm thinking of buying a plug in oven and the ones I'm looking at generally go in as a built in one. I've not had a built in one before and am planning on putting it in where my old freestanding cooker was. I've already filled in the work top in that area so the cooker would go in underneath on some sort of platform, if that makes sense! Is there anything in particular I need to do/prepare? Or can I just slide it in and use it? TIA.