[Online Application] Where to attach sponsorship letter and multiple bank statments

[iLantian]

Hello,

I will be applying online and my sponsor sent me bank statements from 3 banks and each had 4-5 files for each month.
is the best thing to do is to merge the sponsorship letter and the bank statements files in one pdf file ? also each bank statment has last page as an ad or something for the bank should I remove this or leave as it is ?