Syphon fuel or not?

Hi,

I have a 2004 1.9 AWX TDI

Last October I parked it up as since getting it (1 owner service history) it has had timing kit and new turbo and then the dmf and gearbox needed fixing

I was unsure if I was going to keep it but I think I might now as only 105k.

Question is should I syphon the fuel (1/4 tank) been sat since October or should I add biocide and top up?

Whats the risk and how realistic is it of causing damage if I just run it on the diesel thats in there and do nothing to it?

@rotodiesel Appreciate any thoughts you have on this

Thanks,