Well you'd need to do a blenders course first, but TBH, do you really want to
You got a suitable space for the kit?
Your house insurer cool about large quantities of a gas which will support the combustion of just about anything known to mankind?
what about the compressor for the actual 21% part of the mix, you got one already? (your O2 will go in first then the air is added not the other way around
you got the money to setup such a facility?
Put it this way - in my old club (who already had the space and a compressor) we asked the compresor service engineer for a quote on setting up such a system, his recommendation was "Don't bother". Compressors aren't cheap to run and maintain and the danger of large amounts of O2 can't be taken lightly.