Comreg issues the Licence. You must pass an exam.

Essentially there are three areas

1. Regulations
2. Operating Procedure
3. Theory

1) Regulations. You must learn them. You can't guess these answers on the Multiple choice as some seem arbitrary:
Check Comreg for latest and Current Regulations.
Applicable on Oct 2009 From http://www.comreg.ie/publications/latest_publications.597.0.0.2009.p.html
(All PDF downloads. Get Foxit PDF Reader)

• Amateur Radio Licence Guidelines 09/45
• [URL=http://www.comreg.ie/_fileupload/publications/ComReg0945(a).pdf]Application Form - Amateur Station Licence 09/45a[/URL]
• [URL=http://www.comreg.ie/_fileupload/publications/ComReg0945(b).pdf]Amateur Station: Club Licence 09/45b[/URL]
• [URL=http://www.comreg.ie/_fileupload/publications/ComReg0945(c).pdf]Amateur Station: Automatic Station Licence 09/45c[/URL]
• [URL=http://www.comreg.ie/_fileupload/publications/ComReg0945(d).pdf]Amateur Station: Additional Authorisation (Frequency & Power) 09/45d[/URL]
• [URL=http://www.comreg.ie/_fileupload/publications/ComReg0945(e).pdf]Amateur Station: Special Event Licence 09/45e[/URL]
• [URL=http://www.comreg.ie/_fileupload/publications/ComReg0945(f).pdf]Amateur Station: Visitors Temporary Licence 09/45f[/URL]
• SI 192 of 2009 Wireless Telegraphy (Amateur Station Licence) Regulations 2009 (25th May 2009)