The first thing you need to do is to buy Cyrillic stickers for your keyboard from an online store like ebay or your local office store. There you'll find transparent or regular keyboard stickers, and as you can guess you need to purchase the transparent ones always!
The color choices follows like: red, yellow, blue, black, green, grey. And as for me, choose the similar color of the color of of your keyboard letters so that they wont look too flashy awkward. (grey-black, orange-red..)
Besides, you'll only need a tweezer.
Step 1: Preperation
Control Panel >> Region and Language >> Keyboards and Languages >> "click" Change Keyboards >> "click" Add >> "choose" Russian (Russia) >> "tick" Russian >> "click" OK >> "go to desktop and find the language bar on the right side of your taskbar" >> "click" EN (or the abbreviation of your language) >>"select" RU Russian (Russia)
now open a software you can type like notepad and test it..
Android Users (before connecting a Bluetooth keyboard)
Settings >> Language and Input >> Keyboard and Input Methods >> International keyboard >> Writing Languages >> "tick" Russiam (RU) >> "tap" OK
now open an application you can type like watsapp and change the language from the on screen keyboard.. to do this find the "send" button and tap on the EN (or your language abbreviation) to switch RU.. now connect your bluetooth keyboard and test it..
Step 2: Placing Stickers
Clean your keyboard with alcohol and let it dry out before application. Simply use tweezers to place each sticker after you test every single letter..
Step 3: Finalize
TA - TAA!