We get this question a lot right now with social distancing and shelter-in-place restrictions. The simply answer is very carefully. Executing a Will necessitates personal contact. To execute a Will that is "self-proved" (which means it is easy to prove and admit to probate - trust us - you want this), you need two witnesses and a notary to verify your signatures.
We tried the new "online" remote notary process, but when we called the Travis County Probate Court we were told the Court would not accept that "new" type of notarization. So, we have created a "social-distance" acceptable execution process. We call it "drive by" execution. Essentially, you come to my house and pull up next to the curb. You text me and I come out - mask and gloves on - and hand you a clipboard with all of your documents on it with instructions. You then sit in your car and sign everything. You hand it all back to me. Then I go to the witnesses that you have asked to come who are also parked in front of my house. I ask them to sign and pass it to them in their car. I then take the signed documents and I - the notary or my wife (who is also a notary) notarize everything. Viola! Fully signed, notarized and SELF-PROVED DOCUMENTS! You leave with the originals.
We ask that you eventually scan the originals and send us a copy for our records and your protections. Its the best we can do right now. It works. Its not simple. It takes about 20 minutes.
If you want to see what the instructions look like for such an enterprise, I've attached a copy of an example.