1.2htp Gearbox removal help and hints?

Hi there had a sudden no drive problem with 1.2HTP and after a lot of hopeful checking  to no avail reckon its either Diff problem or clutch contaminated/failed Took the slave out and internal gaitor is split with very slight signs of fluid. Fluid leak maybe a lot worse when clutch is pressed. No obvious signs of fluid under car but reckon clutch may be sitting in a puddle of fluid and not managing to drain out of bell housing hence no drive. Even with the slave removed still no drive/contact between engine and gearbox  Tried everything else. Checked drive shafts and they seem good. Reckon need to take gearbox out. Had a quick look on line and tutorials say engine has to be hoisted up slightly with bar across wings when removing mounts. I have no lift or bar so question is can I support engine via sump. Its steel but don't want to crush it or damage it, Has anyone succesfully done this? (Mate put a trolley jack through his sump which was alloy) trying to lift his car. Used to regularly use the ssteel sump on my old volvo 940 but again it was a volvo. Also any tips etc would be appreciated ie. how high do I need to lift the car. Dont want to start then realise I have to lift it an extra inch or two to remove box. Its a 55 plate with 70,000 on clock. Normaly on a car of that age I wouldn't even bother but its in really good condition with no rust and so far everything has come off or apart with ease. Its like working on a new car compared to my other octavias and terminal rusty seat altea xl. 

I had a rear brake leak and front flexi which I have repaired so didn't notice any fluid loss.

Many thanks in advance 

Alasdair