What a load of b*ll*cks
I have replaced my tyres and inner tubes on a number of occasions over the period I have owned my aircraft. I have timed it so that this happens close to or at the 50 hour or annual and have had absolutely no issues with any of the LAEs who have been involved in our maintenance.
Changing tyres and inner tubes is a doddle and anyone who says otherwise is either a rep from an engineering organisation or is a rep from H & S.
The more we get involved in the maintenance of our aircraft, the better. Tyres and inner tubes are probably the easiest item of maintenance of all and a good place to start.
True, you need to be aware of your own limitations, but why not give it a try under supervision