On a Replicator 2 print without Raft and no Support either. The tree prints well with 3 shells / 20% fill and 0.20mm resolution. The star is best printed "with" Raft and prints well with 3 shells and 50% fill to make it almost solid.
Z-Pause build at 3mm (approx. 97% without Raft) and change the colour to add coloured decorations.
Print the star separately. Natural PLA looks great due to its shiny translucent appearance. There is a small amount of designed in support on the base of the star that should be easy to remove. This exposes a longer centre stem that protrudes beyond the lower points of the star. This tem will help slot it securely into the top of the tree (assuming printer is printing accurately)
(1) Recommend levelling build plate before starting this print due to some details on the underside that can come away during the first layer if not well levelled.
If you choose to use Raft the filament change point will need to be adjusted to compensate for the Raft thickness (usually about 1.25mm but varies by machine)