You can select the files you won’t need anymore in the Downloads folder, clean your browser history and send these items to the Trash folder.
To be able to install new apps and download large files you need to free a few gigabytes.
When your Mac runs out of disk space it starts running slow. It encrypts the erased data so that no one will ever get access to it. To get rid of the files permanently, you should use the Secure Empty Trash option. Select Empty Trash and then release the key (s). Press & hold the Option key or the Shift + Alt/Option keys. Click on the Trash icon in the Dock and hold it until the menu pops up.
How to Force Empty Trash on a Mac Using the Option Key.
If you delete unnecessary files from your Mac by moving them to the Trash folder and emptying it, the data still can be restored with the help of special software. Type the Mac user password and press Enter. This is a particularly helpful trick if you’re triaging a very large or cluttered Trash can on a Mac, since you can target individual large files to free up disk space.
The quickest way to remove all trash from the bin in one batch is by using the Option key.
You may have difficulty deleting a file if it’s been locked.Emptying the trash is generally adequate toto get rid of the files you don’t need any longer. If it’s a background process that’s using the file, open Activity Monitor and terminate the process.