Lenovo ThinkPad X390 FHD Core i7-8665U 16GB 256GB - Refurb £299.99 with code (UK Mainland) @ newandusedlaptops4u / eBay

But your £300 new laptop will be a low/mid level processor, in many caes probably a dual core unless you go with AMD, there will be no parts support after the one year warranty runs out. The first deal around the £300 (it's over it) is an AMD 3500U which is ranked slower than this i7 (despite it being newer), has half the RAM and you will not be able to get things like replacement parts such as screens easily for it or with the range of choice you can on a Thinkpad (or Dell/HP equivalent).

These ex-corporate business machines are great value for money and their longivity is fantastic as most of them if they were going to have died would have done so when the company picked them up had them. I've yet to have a refurb Thinkpad fail on me and I still own an X61 from 2007, it's slow but works great and I've had that coming about 10 years now and it was a refurb just like this deal.

My daily driver is a T470 that is from 2017. It works great and the screen hinges are still attached and as tight as when I first got it.

Yes you should be able to do it, if you can change a plug then this isn't much harder different to that, if you can build Ikea furniture then again you'll do dandy.

Lenovo make it very easy to do step by step.

download.lenovo.com/pcc….pd

Page 79 is where you want to go to see the steps involved in swapping the battery, removing the covers is covered elsewhere on the Hardware Maintenance Manual (HMM) elsewhere.