0) download stripped MR3020 image from here http://q.gs/6giYF. Skip the advertising and download archive and unzip archive.
File you need has named "TL-MR3020-V1-FW0.0.3-stripped.bin". The images TP-Link is providing on their website cannot be used directly.
If you want to learn why, please have a look here: http://wiki.openwrt.org/toh/tp-link/tl-mr3020 ("Restore Original Firmware" section).
1) goto to mteobridge "Network" tab
2) click "Expert Options (openwrt)" button
3) login on openwrt as user "root" and the password you have defined for your meteobridge
4) goto openwrt "system" tab, select "firmware / backup" sub tab.
5) select "TL-MR3020-V1-FW0.0.3-stripped.bin" as firmware update file.
6) unmark "keep settings" option
7) start firmware flashing by pressing "proceed"
confirm flashing again and then wait...MR3020 is back in TP-Link style. IP is 192.168.0.254