This assumes that there are no dots in the data. Then you can take this shortcut:
; WITH replace AS (
SELECT replace(col, ',', '.') ASdottedcol
FROM tbl
)
SELECT parsename(dottedcol, 3) AS firstname,
parsename(dottedcol, 2) AS lastname,
parsename(dottedcol, 1) AS age
FROM replace
If there are dots in the data, you will need to use a traditional string splitter with CROSS APPLY. I have more details in this article on my web site: https://www.sommarskog.se/arrays-in-sql.html.