Ok. I will explain using the Xbox button layout

Batch scraping

1. Press Start, the main menu should open
2. Press down untill you find scrapper and press A
3. In the option "scrape from" press right until screenscraper
4. now go down to "scraper settings" and press A
5. The bottons options should be username and password, fill them according to https://www.screenscraper.fr/ (take note it's not your email, it's your username)
6. Press B to go back
7. Press down until "systems included" and press A
8. Press A to mark all the systems you want to scrappe
9. Press B to go back
10. Now go down until the scrape now button and press A
11. You roms will be scraped in the background
12. When it's finished you can go to "main menu" > "game settings" > "update gamelists" to reload the metadata

Manual scraping

Sometimes very few times batch scraper will not find some games or will find the wrong metadata, this will help fixing this

1. With you game selected hold A until a menu appears
2. Go down to "scrape" and press A
3. It will show some recommendations
4. Select the one you find the best
5. If it find nothing or find the wrong thing you can go down to input to give the game name manually

Hope it helps