there is much oral English which disobey grammer rules, for example:
1.How about ...
2.Coffee or tea( In formal English,you should say:Which one would you like,coffe or tea?)
3. cauz ...(It should be :"Because...")
4. I gonna to leave.
If I back to China, I could bring the ielts test book to show you it is right for speaking "how to...".
And sometimes ," How to " become a word "howto".
So, I can say :Could you show me how to do this?
or just say:How to do this?
We want to learn living English ,not only testing English.