How to write two hooks?

Question

WooCommerce

I have two fairly simple tasks, but I broke my head. Somehow I did it with the help of crutches, but is it possible to implement this with the help of hooks? So:

1. Take the price, multiply it by 1.08, draw the result crossed out, and the price itself - below. After it, make the * icon and the line below - an explanation of the conditions.

2. Make it so that the price of the goods in the basket is automatically multiplied by the same 1.08 when choosing one of the payment methods.

The first I implemented by adding an arbitrary field, which is inconvenient.
The price of the item in the cart is multiplied by the plugin, but I would like to display the price change in the cart table too.