the sql patch, that works by running a command in admin>tools>install sql patches
if you go in there, there is a text box, you write in the code and click the button, that executes the code and depending on what the code is, it'll add tables to the database or in this case it updates the price column increasing the price by 10%
UPDATE products SET products_price = products_price * 1.10;
1.10 being 100% of the price and add 10% ontop, if you want to add 45% it would be 1.45
by sticking that line of code in and clicking the button, it should adjust all the prices and add 10% onto them all, thats not my code mind you, its from the other thread so I'v not tested it to see if it works alright,
gordys suggestion would be a good one, means there is nothing to break on the store, adding sql statments could break things if the code isnt right