Updating old Aleph LEs, SF KX2 head

[akula88]

I'm planning to update these :

Will a simple LED/emitter change be possible without updating or changing the circuit? and just re-flowing of LED?

1. old Aleph light engines with Cree Lux-III :
- - A - Downboy-700ma 2004 Rev 3.
- - B - Wiz2-400ma

2. Surefire KX2 heads (E2L Outdoorsman) single and two-mode (L-H)

Are these LEDs possible? -- XPL-HD, HPL-HI, XHP.35, SST-20, Samsung LH351D, Osram Flat White ?