He said he desoldered pin 13 from the module board. That's needed because pin 13 is probably connected to ground under the 125 chip. You have to break that connection. Also, you need to make sure that your 125 pinout is the same as his.
There are two other ways to solve this problem:
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If you can find the trace that connects the 125's MISO output to the MISO header pin, you can cut that, then connect the header pin directly to the MISO pin of the SD holder, bypassing the 125. The SD card itself should behave properly and release MISO when its CS isn't selected. And since MISO is an output of the SD card at 3.3V, you don't need to translate it to 3.3V in the 125 anyway.
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It is reported that you can fix this by inserting a resistor in series somewhere in the connection from the MISO ouput of the 125 and the MISO input of the Arduino. I don't specifically remember the value of the resistor, but it might be 3.3K. When the SD card is selected, the resistor isn't enough to interfere with the transmission, particularly since the other SPI device has released its MISO. And when the other SPI device is selected, the resistor just behaves as a pullup or pulldown resistor which does not prevent the other device from taking MISO to whatever state it wants. You would need to experiment with the resistor value. Too high a value would limit your speed.
I'll attach a drawing showing fix #1.
By the way, I've never seen a microSD module that does not have this problem. Maybe the module makers of the Far East will do it right at some point.
