I tried pasting that into SSMS and hitting F5, but got a parsing error.

You clearly have not taken the time to read the article to which Jeff directed you. Or,...

This expression will do that:

right(F,3) == "\" \""? replace(F,"\" \"","\""): F

OK, just to be clear, are you saying that you want to change this

"1234-28" "

to this

"1234-28"

?

Still using SSMS 18.x since my second most important Addon (besides Redgate SQL Prompt) with the name SSMSBoost seems to be deprecated and there is no version that works...

Note also that there is a difference between an empty string ("") and NULL.

Please try this:

REPLACE( F , "\"", "" )

Once again, if you want coding assistance, please provide consumable sample data for us to experiment with.

This semi-join version of the UPDATE might perform better

UPDATE pt
SET LastModifiedDateTime = @dt
FROM PlayersTypes pt
WHERE EXISTS
(
    SELECT 1
    FROM @TableTypePlayersTypes ttpt
...

First you check whether the table has data. Then you obtain the...

Are you sure that this will improve performance? It's going to introduce a lot of code 'waffle', which looks inelegant to me.

Please provide your sample data in the form of CREATE TABLE/INSERT statements and also provide your desired results.

As far as I can remember, Windows...

Redgate Clone, perhaps? (Link)

Having Access run a stored proc to execute a package deployed to SSISDB is the way to go. Any other way is likely to violate software licensing.

If you don't currently...

OK, good. So what is it that you are not able to do, exactly?