If you need to replace anything other than your iPhone 8's battery or display, good luck
https://www.theregister.co.uk/2017/09/22/ifixit_iphone8_repairability_verdict/
iFixit’s teardown of the new iPhone 8 confirms that the screen and battery remain relatively replaceable, despite the addition of Qi-compatible wireless charging coils in the unit.
Overall the site gives the 8 6/10 for repairability… the same score as last year. The iPhone 3GS in 2009 was given a 7/10 and only needed three tools, and one screwdriver. It’s a different story these days.