injector pump problems

[toyboata]

I brought back my old surf yesterday. drove it home no problems went and started it up this morning and after a few seconds it started leaking diesel everywhere. i think we have found the problem from the injector pump. it looks to be leaking from the back of the pump were there are 2 what look like hex bolts on an oval plate. it is leaking horrendous.
any ideas what to do next? is a new pump in order or a seal kit? and how hard is the job to do?