Swapping relays with transistors

I’ve checked the 202U v6c with a Digital Multi-Meter and while supplying the minimum required (9V) to the remote receiver, the current drawn seems to be ~10mA during idle with an extra 100 mA per relay if these are on.
I am trying to use this receiver in a setup where my battery capacity is highly limited, so I was wondering if it would be possible to change the relays for transistors (acting as a switch). Is it as straight forward as desoldering the relays and soldering in the transistors with a resistor to avoid burning them?

Thank you again for this great product you offer!

Well, it is possible, we use a PNP transistor to control the +5Vdc relays.
The circuit is similar to the one below.

From https://electronics.stackexchange.com/questions/277595/preferred-way-of-interfacing-relay-coil-with-active-low-output-from-mcu

When +5Vdc is applied via transistor, the relay is turned on.

But still the standby current is ~10mA, might not be suitable for battery application, maybe you can check products from other suppliers, that has a lower standby current.

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Thank you, sir. I’ve been looking at the board and now I can see the 2 resistors and 2 transistors used for this. It should be pretty straight forward. Ideally, I would remove the transistor and connect it to my micro-controller directly from the resistor. However, since my soldering skills are not so great, I may have to remove the relay instead and use the connection that would normally go to the coil.

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