Please enter a positive decimal. Mail your donation to Ronald McDonald House Charities of San Antonio, 4847 Charles Katz San Antonio, Texas 78229 or use our secure online form below.Find information for the CSL Plasma Donation Center in San Antonio, TX , including hours, services, and directions. Do the Amazing and Donate Plasma today! We would be happy to donate to your event. The City Manager has the authority to receive donations and contributions on behalf of the City without prior City. How to use this form: A. Print, Fill Out legibly in pen then Mail form with your tax-deductible donation. In this post, I'm breaking down how to write a donation letter. Below simply fill out this form and make your donation count TWICE! Yes, I will make a commitment for a donation.