ESA to UC, managed migration

I was sent a letter by ESA saying I will be paid new style ESA & it will be deducted from my UC, then a journal entry from UC asking about the ESA.This is messing with my brain, extra stress not needed. The only thing I can find out is, though UC pays some contributions towards your pension, ESA new style pays a higher one, uis. this correct?

Why have they not explained why there are these added things, as well as completing the claim itself online? I have a fair bit of knowledge & know my way round basic online stuff, but many won’t & will panic.