I broke off one of the antenna connectors when I took off the antenna wires, but the new 802.11ac card is working:) I seems the way to take off the wires is lifting it up from the wire side. In hindsight I just wasn´t careful enough.
I addition to the two Torx5 screws, My Wi Fi bluetooth card was glued to the main board with a grey porous glue that was easy to peel off once I got the card loose.
I found a connector for SSD there on my iMac that came with 1TB HDD! Found it when I had to remove the main board to upgrade the Wi Fi card to 802.11ac:) I might be very lucky or some base 21.5" iMacs have the connector even though the one in this teardown didn´t have it.
I successfully upgraded the Wi-Fi Bluetooth card in my late 2012 iMac to 802.11ac following this guide! The new card is now the same as what´s in the new 2013 iMacs, I used the 2013 iMac teardown to find the right part:)