the Belarusian security forces are not as loyal to the Lukashenko regime as you think. They are all part of the same social fabric, they have mothers, brothers sisters who are among the population. The oppositions successful unmasking of them has been a massive spanner in the strategy of Lukashenko oppression.
What they are missing is being able to defend themselves from Wagner group mercenaries who have absolutely no such ties and couldn't care about who they kill. Sending mercenaries and arms with a mission to take out the Lukashenko regime while fighting the Russians who are infiltrating the security forces would be the only strategy.
Helping in other ways (from the comfort of an arm chair) is possible but it means cracking down on off-shore banking and money laundering (much of it takes place in Europe & the US. Good luck.
That's pretty much how this has been working throughout the history of the human race.