just been and brought a darrel a/c unit for my house only to find the manual is in every language but english. I plan to fit the unit myself i am a maint eng but have no experience with a/c basicaly my question is do i have a pope in hell of fitting it myself will be pre gassed (how do i tell) will 1200btu be enough to cool your average 3bed semi

thanks for looking and your help
mark