Anyone tried to redecorate M&S Rainbow cake?

[Lily7050]

Basically I would like to remove sprinkles from the sides of M&S rainbow cake and add different sprinkles and edible images.
Just wondering if anyone here have tried to redecorate M&S rainbow cake? Do I need extra buttercream to cover sides once the original sprinkles removed or there is enough buttercream on the cake, so I can just smoothen sides and add new sprinkles and other decorations?

Yes, scrape off with a palette knife (or similar) and depending on size of cake you'll need a full batch of buttercream. If you want a colour match you might as well scrape & replace the top as well. I don't know how experienced you are so hope you'll not mind me reminding you to use a pint of hot water to dip your knife to smooth the icing. For the new layer do the sides first, then the top, then whatever decoration edges and borders. Lots on YouTube to give you confidence.

Thanks @Firsttimecaller .