Hard reset Fritzbox 7360 v2

[pc_magas]

I misconfigured network settings as a result I am unable to connect into Openwrt using ssh.
Is there a way to hard reset the router modem. Router itself has no reset button and connecting via WLan does snot help either.

Is there a way to reflash/reset openwrt and start over again?

AnythingI have looped upon there did not help me:

Failsafe Mode, Factory Reset, and Recovery Mode

The reason why I failed to connect is, because I misconfigured the /etc/config/network as an attemp to set up the router as a device in my lan with static IP.

Is there a way to reset the initial settings?

The installation instructions in order to install OpenWrt are the following: https://openwrt.org/toh/avm/avm_fritz_box_7360_v2

Also in this router how I can connect a serial device as well? Is a USB keyboard a valid one?

[slh]

Repeatedly pressing any button repeatedly during early boot 'should' get you into the recovery mode. If that fails, you can also reflash OpenWrt from AVM's bootloader (ADAM2) via ftp, just like you did initially.

[pc_magas]

What is the ip I should whilst booting so I can reflash it? After openwrt I have the 192.168.1.1 but that due to misconfiguration is unaccessible.

[slh]

The failsafe environment always comes up with 192.168.1.1, no DHCPd.

[pc_magas]

Complimenting the @slh answer:
In older to solve the problem I did the following.

1. Powered off my router
2. Connected an ethernet cable from routerts physical ethernet port LAN1 to my computer's ethernet port
3. Set up my computer's wired ethernet connection with static ip 192.168.1.2 mask /24 (255.255.255.0) and network gateway 192.168.1.1
4. Powered on the router
5. pressing both DECT and WLAN like a maniac ,as this musician was pressing the piano key, till power led comes red.
6. Then I ssh via ssh root@192.168.1.1
7. Once I managed to have an ssh session as guide says I did:

   mount_root
   

8. Then I fixed my network settings.