Hi, it looks like you have 2 different questions here. Was your original question on how to wipe a drive for a return answered?
About your eeepc. They came with 2 ssd drives. 1 small one soldered into the motherboard, and a larger drive that can be removed.
If you are looking to start from scratch and erase both drives, using the smaller one for your install and the larger one for your personal files do the following.
Boot up a live USB of your choice
Open gparted and find the smaller drive
Delete any existing partitions
Create 1 partition formatted to ext4
Do not create a swap ( the drive is to small for it)
Now find the larger drive
Delete everything any existing partitions
Create a 2GB swap partition
Create a ext4 partition with the rest of the free space
Run the Linux Mint installer
When it comes time to choose a disk, select custom or " something else"
Double click on the smaller partition and select " use as /"
Now double click the largest partition and select " use as /home/"
There is a selector for the boot loader. Make sure it's the same as the smaller drive that your system is going to get installed on. (Example SDA)
Continue on with the installation.