A guide funnel includes segments that have a funnel surface running at an oblique angle between a bottom end and an inner circumferential edge of the top end. The width of the funnel surface is sized so that, when the guide funnel is in an assembled state, a continuous or discontinuous funnel wall is formed between adjacent segments. The bottom end can include an arcuate-shaped ring segment that forms a portion of an outer periphery of the guide funnel. The top end can be sized so that when the guide funnel is in the assembled state a side of the top end abuts a side of an adjacent top end. An adaptor ring can be secured to the inner circumferential edge of the top end and later removed and replaced with another adaptor ring to provide a different size guide funnel.