Bypass read-only SD card with missing 'Lock' slider

From sd card reader not working :

I found that unlocked, my Eye-Fi card should only be inserted 20-22mm into the card reader (not all the way). Locked, it seemed to work fine inserted all the way.

Another solution from Repair missing SD-card lock :

1. Get a piece of aluminum foil and stick it onto a piece of tape then put it on SD :
   

2. Cut a straw into pieces that can fit into the hole of the Lock and fill the hole with them and cover with the other end of a scotch-tape. Use 2-3 pieces of straw :
   

3. Insert into the card-reader :
   

The write protection tells the computer to reject all write requests, which normally prevents writing to the SD card. Unlike the floppy disk, this is done at the software level. Although the card reader can detect the position of the read-only switch, the switch itself doesn't physically hinder writing. This means that although it's theoretically possible to write onto a read-only card, it would have to be at a low level. Barring direct manipulation of the output bits, the only permanent solution would be to format your card at a low level, thus removing the card-side write protection.

This is not the same as a normal formatting. It wipes the card completely, including the protected areas, where the write-protection securities would be held. Theoretically, this would erase the card's write protection, but it may also come with unforeseen complications if done incorrectly. I would suggest that you only use a low-level format if you know exactly what you're doing. There is a free low-level format tool compatible with SD cards available at this link: http://hddguru.com/software/HDD-LLF-Low-Level-Format-Tool/

It should be noted that this needs to be done in conjunction with one of the hardware solutions posted here. Again, SD card readers are designed so that they can detect the position of the switch. If the hardware solution doesn't work (as is the case here), then the card must also have a built-in write protection.

I'm fairly certain that the lock is a physical mechanism, and therefore all you need to do is put a piece of scotch tape over the SD card. Be very precise in placing the tape over the notch, but not over the brass connector on the opposite side.

The notch forces the read-only to work with camera's, PDA's, MP3 players, etc, however they are not guaranteed to work on all SD readers (apparently it works on your reader). It's simply a physical thing, therefore the tape will trick the SD card reader into thinking the SD card is unlocked.