This question needs to be dealt with directly by the Deutsche Rentenversicherung - German Statutory Pension Insurance Scheme.
Unfortunately, the Embassy is unable to replace a German drivers licence.
If you still have a registered residence in Germany, you may apply at the respective drivers licence office in Germany. If you don’t have a registered residence anymore, the office in Germany usually won’t take your application according to our experience. In that case, you need to apply for a new licence at the Irish National Drivers Licence Service (NDLS). You can find details about the application process under www.ndls.ie
You are o.k. to travel as long as your Irish/EU passport is still valid on the day of your return journey.