Send a generic message to 1700 profiles on a web platform

I'm looking for someone to help me send the same message to 1700 profile on a web platform, with the only difference between these messages being the first name replaced in "Dear [x],".

The whole process is very quick and takes a few seconds each:
- Click on the profile name on the directory
- Click "Send Invitation"
- Select the only opportunity there in the dropdown field
- Copy paste the same subject
- Copy paste the message and insert into the "[WRITE YOUR PERSONAL MESSAGE HERE]"
- Change the "Dear 'X" with X being the first name on the profile.
- Click "Send Invitation"

I need assistance as soon as possible, let me know when you're available to do this and when you can finish it.