The real answer is you you shouldn't speed it up.
10 minutes is an AVERAGE block time, but in theory it can be much faster for 2 weeks if you put in lots and lots of additional hash power into network. However this time is there to make sure network is stable and robust, you shouldn't aim to speed it up. There are plenty of solutions offering instant bitcoin transactions and LN will be instant settlement.
How about change 2 weeks to just 1 day? or even 1 hour? Then lots and lots of hash power can't ruin?
The 2 weeks he's talking about is bitcoin's
difficulty retarget/adjustment in which the rate of blocks being found increases or decreases based on the average hashrate for the last 2016 blocks (2 weeks)
You can change the difficulty period to less than 2016 blocks but depending on how you implement it it can
lead to disaster