First download putty, run putty and connect telnet session to your box. User root, probably no password (simply press enter)
Then download any oscam for KI, KII, KIII. Upload manualy using ftp client like Total Commander od Double Commander or via wget.
Code
wget https://dl.sourceforge.net/OScam/enigma2-softcams-oscam-all-images_11.714-emu-r798-arm-mips_all.ipk
opkg update
opkg install nigma2-softcams-oscam-all-images_11.714-emu-r798-arm-mips_all.ipk
Upload your config file or run oscam without valid configs, but in that case you may have problem login to oscam webinterface.
See whats happen.