Slapping anything in the headlight is a recipe for disaster. Think carefully and plan it before going balls out. Most japs do underlines or over lines of led strips, on the exterior of the light top & or bottom. Check your Pm's :D
Pretty sure it can be done. I done mine at Autojoy in Granville. 4 rings is usually $450 but if you pay cash they'll do it for $400. Their website is www.autojoy.com.au so you can see their photos of all types of cars with the rings.