You know, the white stuff around the edge? Mine is absolutely minging and going black so it needs to be done. I've tried to do it myself numerous times but I'm just making it look bloody worse! I'm not the best at DIY and don't have anyone who can help, relative or partner etc. My hands / arms aren't physically strong enough to pull out the old stuff. I've tried using a knife to pull out what I can and seal with the new stuff but it is actually much harder than it looks and I just end up with numb hands! Even squeezing it out of the bottle is hard. It seems like such a basic thing to pay a tradesman for though, they'll probably laugh at me!